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1210221220 = 225134654697
BaseRepresentation
bin100100000100010…
…1000001010100100
310010100020121102011
41020020220022210
54434304034340
6320031124004
741663465515
oct11010501244
93110217364
101210221220
1157115812a
12299373604
13163962940
14b6a30a0c
15713a90ea
hex482282a4

1210221220 has 24 divisors (see below), whose sum is σ = 2736962424. Its totient is φ = 446850816.

The previous prime is 1210221203. The next prime is 1210221241. The reversal of 1210221220 is 221220121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 121749156 + 1088472064 = 11034^2 + 32992^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 1210221220.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2327089 + ... + 2327608.

It is an arithmetic number, because the mean of its divisors is an integer number (114040101).

Almost surely, 21210221220 is an apocalyptic number.

1210221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1210221220 is an abundant number, since it is smaller than the sum of its proper divisors (1526741204).

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

1210221220 is a wasteful number, since it uses less digits than its factorization.

1210221220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4654719 (or 4654717 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1210221220 is about 34788.2339304541. The cubic root of 1210221220 is about 1065.6671728995.

Adding to 1210221220 its reverse (221220121), we get a palindrome (1431441341).

The spelling of 1210221220 in words is "one billion, two hundred ten million, two hundred twenty-one thousand, two hundred twenty".

Divisors: 1 2 4 5 10 13 20 26 52 65 130 260 4654697 9309394 18618788 23273485 46546970 60511061 93093940 121022122 242044244 302555305 605110610 1210221220