21456604972 has 12 divisors (see below), whose sum is σ = 40962609576. Its totient is φ = 9753002240.

The previous prime is 21456604951. The next prime is 21456604993. The reversal of 21456604972 is 27940665412.

It is an interprime number because it is at equal distance from previous prime (21456604951) and next prime (21456604993).

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, 243825013 + ... + 243825100.

It is an arithmetic number, because the mean of its divisors is an integer number (3413550798).

Almost surely, 2^21456604972 is an apocalyptic number.

21456604972 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21456604972 is a deficient number, since it is larger than the sum of its proper divisors (19506004604).

21456604972 is a wasteful number, since it uses less digits than its factorization.

21456604972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487650128 (or 487650126 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 46.

The spelling of 21456604972 in words is "twenty-one billion, four hundred fifty-six million, six hundred four thousand, nine hundred seventy-two".