21650656 has 24 divisors (see below), whose sum is σ = 45133200. Its totient is φ = 10188288.

The previous prime is 21650653. The next prime is 21650683. The reversal of 21650656 is 65605612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21650653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19356 + ... + 20443.

It is an arithmetic number, because the mean of its divisors is an integer number (1880550).

Almost surely, 2^21650656 is an apocalyptic number.

It is an amenable number.

21650656 is an abundant number, since it is smaller than the sum of its proper divisors (23482544).

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

21650656 is a wasteful number, since it uses less digits than its factorization.

21650656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39826 (or 39818 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 21650656 is about 4653.0265419402. The cubic root of 21650656 is about 278.7128677572.

The spelling of 21650656 in words is "twenty-one million, six hundred fifty thousand, six hundred fifty-six".