21646056 has 16 divisors (see below), whose sum is σ = 54115200. Its totient is φ = 7215344.

The previous prime is 21646043. The next prime is 21646057. The reversal of 21646056 is 65064612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21646057) 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, 450936 + ... + 450983.

It is an arithmetic number, because the mean of its divisors is an integer number (3382200).

Almost surely, 2^21646056 is an apocalyptic number.

It is an amenable number.

21646056 is an abundant number, since it is smaller than the sum of its proper divisors (32469144).

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

21646056 is a wasteful number, since it uses less digits than its factorization.

21646056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 901928 (or 901924 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 21646056 is about 4652.5322137520. The cubic root of 21646056 is about 278.6931274777.

The spelling of 21646056 in words is "twenty-one million, six hundred forty-six thousand, fifty-six".