21553160 has 16 divisors (see below), whose sum is σ = 48494700. Its totient is φ = 8621248.

The previous prime is 21553157. The next prime is 21553183. The reversal of 21553160 is 6135512.

It can be written as a sum of positive squares in 2 ways, for example, as 20557156 + 996004 = 4534^2 + 998^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 269375 + ... + 269454.

Almost surely, 2^21553160 is an apocalyptic number.

21553160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21553160 is an abundant number, since it is smaller than the sum of its proper divisors (26941540).

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

21553160 is a wasteful number, since it uses less digits than its factorization.

21553160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538840 (or 538836 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 21553160 is about 4642.5380989282. The cubic root of 21553160 is about 278.2938769014.

Adding to 21553160 its reverse (6135512), we get a palindrome (27688672).

The spelling of 21553160 in words is "twenty-one million, five hundred fifty-three thousand, one hundred sixty".