21120019960 has 64 divisors (see below), whose sum is σ = 52042888800. Its totient is φ = 7665977856.

The previous prime is 21120019937. The next prime is 21120019961. The reversal of 21120019960 is 6991002112.

It is a super-2 number, since 2×21120019960² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120019961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 313519 + ... + 374878.

Almost surely, 2^21120019960 is an apocalyptic number.

21120019960 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120019960 is an abundant number, since it is smaller than the sum of its proper divisors (30922868840).

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

21120019960 is a wasteful number, since it uses less digits than its factorization.

21120019960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 688480 (or 688476 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 31.

The spelling of 21120019960 in words is "twenty-one billion, one hundred twenty million, nineteen thousand, nine hundred sixty".