21561152 has 28 divisors (see below), whose sum is σ = 44264580. Its totient is φ = 10407936.

The previous prime is 21561131. The next prime is 21561167. The reversal of 21561152 is 25116512.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 9339136 + 12222016 = 3056^2 + 3496^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3953 + ... + 7664.

Almost surely, 2^21561152 is an apocalyptic number.

It is an amenable number.

21561152 is an abundant number, since it is smaller than the sum of its proper divisors (22703428).

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

21561152 is a wasteful number, since it uses less digits than its factorization.

21561152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11658 (or 11648 counting only the distinct ones).

The product of its digits is 600, while the sum is 23.

The square root of 21561152 is about 4643.3987552223. The cubic root of 21561152 is about 278.3282701538.

Adding to 21561152 its reverse (25116512), we get a palindrome (46677664).

The spelling of 21561152 in words is "twenty-one million, five hundred sixty-one thousand, one hundred fifty-two".