21079956 has 12 divisors (see below), whose sum is σ = 49186592. Its totient is φ = 7026648.

The previous prime is 21079931. The next prime is 21079979. The reversal of 21079956 is 65997012.

21079956 is nontrivially palindromic in base 14.

It is a tau number, because it is divible by the number of its divisors (12).

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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, 878320 + ... + 878343.

Almost surely, 2^21079956 is an apocalyptic number.

It is an amenable number.

21079956 is an abundant number, since it is smaller than the sum of its proper divisors (28106636).

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

21079956 is a wasteful number, since it uses less digits than its factorization.

21079956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1756670 (or 1756668 counting only the distinct ones).

The product of its (nonzero) digits is 34020, while the sum is 39.

The square root of 21079956 is about 4591.2913216218. The cubic root of 21079956 is about 276.2421210805.

The spelling of 21079956 in words is "twenty-one million, seventy-nine thousand, nine hundred fifty-six".