21657170012 has 24 divisors (see below), whose sum is σ = 38005380000. Its totient is φ = 10798526016.

The previous prime is 21657169999. The next prime is 21657170023. The reversal of 21657170012 is 21007175612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3113114 + ... + 3120062.

It is an arithmetic number, because the mean of its divisors is an integer number (1583557500).

Almost surely, 2^21657170012 is an apocalyptic number.

It is an amenable number.

21657170012 is a deficient number, since it is larger than the sum of its proper divisors (16348209988).

21657170012 is a wasteful number, since it uses less digits than its factorization.

21657170012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9005 (or 9003 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 32.

The spelling of 21657170012 in words is "twenty-one billion, six hundred fifty-seven million, one hundred seventy thousand, twelve".