21171038156 has 12 divisors (see below), whose sum is σ = 37571138640. Its totient is φ = 10436427120.

The previous prime is 21171038149. The next prime is 21171038191. The reversal of 21171038156 is 65183017112.

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, 37272671 + ... + 37273238.

It is an arithmetic number, because the mean of its divisors is an integer number (3130928220).

Almost surely, 2^21171038156 is an apocalyptic number.

It is an amenable number.

21171038156 is a deficient number, since it is larger than the sum of its proper divisors (16400100484).

21171038156 is a wasteful number, since it uses less digits than its factorization.

21171038156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74545984 (or 74545982 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 35.

The spelling of 21171038156 in words is "twenty-one billion, one hundred seventy-one million, thirty-eight thousand, one hundred fifty-six".