21079556 has 12 divisors (see below), whose sum is σ = 36997968. Its totient is φ = 10508712.

The previous prime is 21079537. The next prime is 21079567. The reversal of 21079556 is 65597012.

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, 6206 + ... + 8981.

It is an arithmetic number, because the mean of its divisors is an integer number (3083164).

Almost surely, 2^21079556 is an apocalyptic number.

It is an amenable number.

21079556 is a deficient number, since it is larger than the sum of its proper divisors (15918412).

21079556 is a wasteful number, since it uses less digits than its factorization.

21079556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15538 (or 15536 counting only the distinct ones).

The product of its (nonzero) digits is 18900, while the sum is 35.

The square root of 21079556 is about 4591.2477606855. The cubic root of 21079556 is about 276.2403738038.

The spelling of 21079556 in words is "twenty-one million, seventy-nine thousand, five hundred fifty-six".