21152656 has 20 divisors (see below), whose sum is σ = 46838272. Its totient is φ = 9065376.

The previous prime is 21152591. The next prime is 21152657. The reversal of 21152656 is 65625112.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (21152657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94320 + ... + 94543.

Almost surely, 2^21152656 is an apocalyptic number.

It is an amenable number.

21152656 is an abundant number, since it is smaller than the sum of its proper divisors (25685616).

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

21152656 is a wasteful number, since it uses less digits than its factorization.

21152656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188878 (or 188872 counting only the distinct ones).

The product of its digits is 3600, while the sum is 28.

The square root of 21152656 is about 4599.2016698553. The cubic root of 21152656 is about 276.5593222378.

Adding to 21152656 its reverse (65625112), we get a palindrome (86777768).

The spelling of 21152656 in words is "twenty-one million, one hundred fifty-two thousand, six hundred fifty-six".