21097990962 has 12 divisors (see below), whose sum is σ = 45712313790. Its totient is φ = 7032663648.

The previous prime is 21097990961. The next prime is 21097990973. The reversal of 21097990962 is 26909979012.

It can be written as a sum of positive squares in only one way, i.e., 21080426481 + 17564481 = 145191^2 + 4191^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21097990899 and 21097990908.

It is not an unprimeable number, because it can be changed into a prime (21097990961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 586055287 + ... + 586055322.

Almost surely, 2^21097990962 is an apocalyptic number.

21097990962 is an abundant number, since it is smaller than the sum of its proper divisors (24614322828).

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

21097990962 is a wasteful number, since it uses less digits than its factorization.

21097990962 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1172110617 (or 1172110614 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The spelling of 21097990962 in words is "twenty-one billion, ninety-seven million, nine hundred ninety thousand, nine hundred sixty-two".