21121968762 has 24 divisors (see below), whose sum is σ = 45776293524. Its totient is φ = 7038805824.

The previous prime is 21121968743. The next prime is 21121968797. The reversal of 21121968762 is 26786912112.

It can be written as a sum of positive squares in 2 ways, for example, as 19608680961 + 1513287801 = 140031^2 + 38901^2 .

It is a super-2 number, since 2×21121968762² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 82923 + ... + 221630.

Almost surely, 2^21121968762 is an apocalyptic number.

21121968762 is an abundant number, since it is smaller than the sum of its proper divisors (24654324762).

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

21121968762 is a wasteful number, since it uses less digits than its factorization.

21121968762 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308414 (or 308411 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The spelling of 21121968762 in words is "twenty-one billion, one hundred twenty-one million, nine hundred sixty-eight thousand, seven hundred sixty-two".