21216156174 has 20 divisors (see below), whose sum is σ = 47539905864. Its totient is φ = 7072052004.

The previous prime is 21216156167. The next prime is 21216156187. The reversal of 21216156174 is 47165161212.

21216156174 is a `hidden beast` number, since 2 + 1 + 21 + 6 + 1 + 561 + 74 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 65481802 + ... + 65482125.

Almost surely, 2^21216156174 is an apocalyptic number.

21216156174 is an abundant number, since it is smaller than the sum of its proper divisors (26323749690).

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

21216156174 is a wasteful number, since it uses less digits than its factorization.

21216156174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130963941 (or 130963932 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

It can be divided in two parts, 2121 and 6156174, that added together give a triangular number (6158295 = T₃₅₀₉).

The spelling of 21216156174 in words is "twenty-one billion, two hundred sixteen million, one hundred fifty-six thousand, one hundred seventy-four".