21084656 has 20 divisors (see below), whose sum is σ = 41346312. Its totient is φ = 10414656.

The previous prime is 21084649. The next prime is 21084673. The reversal of 21084656 is 65648012.

It is a congruent number.

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, 6611 + ... + 9266.

Almost surely, 2^21084656 is an apocalyptic number.

It is an amenable number.

21084656 is a deficient number, since it is larger than the sum of its proper divisors (20261656).

21084656 is a wasteful number, since it uses less digits than its factorization.

21084656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15968 (or 15962 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 32.

The square root of 21084656 is about 4591.8031316684. The cubic root of 21084656 is about 276.2626499261.

The spelling of 21084656 in words is "twenty-one million, eighty-four thousand, six hundred fifty-six".