21221708162 has 18 divisors (see below), whose sum is σ = 32040650019. Its totient is φ = 10541941060.

The previous prime is 21221708159. The next prime is 21221708177. The reversal of 21221708162 is 26180712212.

It can be written as a sum of positive squares in only one way, i.e., 10610854081 + 10610854081 = 103009^2 + 103009^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=103009.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 49238087 + ... + 49238517.

Almost surely, 2^21221708162 is an apocalyptic number.

21221708162 is a deficient number, since it is larger than the sum of its proper divisors (10818941857).

21221708162 is an frugal number, since it uses more digits than its factorization.

21221708162 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1342 (or 672 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

Multiplying 21221708162 by its sum of digits (32), we get a square (679094661184 = 824072²).

The spelling of 21221708162 in words is "twenty-one billion, two hundred twenty-one million, seven hundred eight thousand, one hundred sixty-two".