21065697672 has 48 divisors (see below), whose sum is σ = 54542925840. Its totient is φ = 6779758272.

The previous prime is 21065697661. The next prime is 21065697683. The reversal of 21065697672 is 27679656012.

It is an interprime number because it is at equal distance from previous prime (21065697661) and next prime (21065697683).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 501658 + ... + 542025.

It is an arithmetic number, because the mean of its divisors is an integer number (1136310955).

Almost surely, 2^21065697672 is an apocalyptic number.

It is an amenable number.

21065697672 is an abundant number, since it is smaller than the sum of its proper divisors (33477228168).

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

21065697672 is a wasteful number, since it uses less digits than its factorization.

21065697672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043750 (or 1043717 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 51.

The spelling of 21065697672 in words is "twenty-one billion, sixty-five million, six hundred ninety-seven thousand, six hundred seventy-two".