21216015161556 has 24 divisors (see below), whose sum is σ = 52109510923680. Its totient is φ = 6699794261472.

The previous prime is 21216015161531. The next prime is 21216015161573. The reversal of 21216015161556 is 65516151061212.

It is a super-2 number, since 2×21216015161556² (a number of 27 digits) contains 22 as substring.

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, 46526348811 + ... + 46526349266.

It is an arithmetic number, because the mean of its divisors is an integer number (2171229621820).

Almost surely, 2^{21216015161556} is an apocalyptic number.

It is an amenable number.

21216015161556 is an abundant number, since it is smaller than the sum of its proper divisors (30893495762124).

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

21216015161556 is a wasteful number, since it uses less digits than its factorization.

21216015161556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93052698103 (or 93052698101 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 42.

The spelling of 21216015161556 in words is "twenty-one trillion, two hundred sixteen billion, fifteen million, one hundred sixty-one thousand, five hundred fifty-six".