Search a number
-
+
1221400 = 235231197
BaseRepresentation
bin100101010001100011000
32022001110001
410222030120
5303041100
642102344
713244635
oct4521430
92261401
101221400
11764724
124aa9b4
13339c2b
1423b18c
15191d6a
hex12a318

1221400 has 48 divisors (see below), whose sum is σ = 2946240. Its totient is φ = 470400.

The previous prime is 1221391. The next prime is 1221421. The reversal of 1221400 is 41221.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6102 + ... + 6298.

It is an arithmetic number, because the mean of its divisors is an integer number (61380).

21221400 is an apocalyptic number.

1221400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1473120).

1221400 is an abundant number, since it is smaller than the sum of its proper divisors (1724840).

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

1221400 is a wasteful number, since it uses less digits than its factorization.

1221400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 235 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 1221400 is about 1105.1696702317. The cubic root of 1221400 is about 106.8938301124.

Adding to 1221400 its reverse (41221), we get a palindrome (1262621).

It can be divided in two parts, 12 and 21400, that added together give a palindrome (21412).

The spelling of 1221400 in words is "one million, two hundred twenty-one thousand, four hundred".

Divisors: 1 2 4 5 8 10 20 25 31 40 50 62 100 124 155 197 200 248 310 394 620 775 788 985 1240 1550 1576 1970 3100 3940 4925 6107 6200 7880 9850 12214 19700 24428 30535 39400 48856 61070 122140 152675 244280 305350 610700 1221400