21216725154 has 48 divisors (see below), whose sum is σ = 46605502944. Its totient is φ = 6975072000.

The previous prime is 21216725147. The next prime is 21216725171. The reversal of 21216725154 is 45152761212.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 356754 + ... + 411954.

It is an arithmetic number, because the mean of its divisors is an integer number (970947978).

Almost surely, 2^21216725154 is an apocalyptic number.

21216725154 is an abundant number, since it is smaller than the sum of its proper divisors (25388777790).

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

21216725154 is a wasteful number, since it uses less digits than its factorization.

21216725154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55503 (or 55500 counting only the distinct ones).

The product of its digits is 33600, while the sum is 36.

The spelling of 21216725154 in words is "twenty-one billion, two hundred sixteen million, seven hundred twenty-five thousand, one hundred fifty-four".