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1220231220 = 2235131564399
BaseRepresentation
bin100100010111011…
…0100000000110100
310011001002011112220
41020232310000310
54444334344340
6321025442340
742144536265
oct11056640064
93131064486
101220231220
1157687485a
122a07a03b0
13165a58c10
14b80b896c
15721d4ed0
hex48bb4034

1220231220 has 48 divisors (see below), whose sum is σ = 3679468800. Its totient is φ = 300364416.

The previous prime is 1220231171. The next prime is 1220231227. The reversal of 1220231220 is 221320221.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1220231220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220231227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 781420 + ... + 782979.

It is an arithmetic number, because the mean of its divisors is an integer number (76655600).

Almost surely, 21220231220 is an apocalyptic number.

1220231220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1220231220 is an abundant number, since it is smaller than the sum of its proper divisors (2459237580).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1220231220 is a wasteful number, since it uses less digits than its factorization.

1220231220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564424 (or 1564422 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 1220231220 is about 34931.8081410052. The cubic root of 1220231220 is about 1068.5972301045.

Adding to 1220231220 its reverse (221320221), we get a palindrome (1441551441).

The spelling of 1220231220 in words is "one billion, two hundred twenty million, two hundred thirty-one thousand, two hundred twenty".

Divisors: 1 2 3 4 5 6 10 12 13 15 20 26 30 39 52 60 65 78 130 156 195 260 390 780 1564399 3128798 4693197 6257596 7821995 9386394 15643990 18772788 20337187 23465985 31287980 40674374 46931970 61011561 81348748 93863940 101685935 122023122 203371870 244046244 305057805 406743740 610115610 1220231220