21956309494372 has 48 divisors (see below), whose sum is σ = 44775036315072. Its totient is φ = 9309948999680.

The previous prime is 21956309494331. The next prime is 21956309494391. The reversal of 21956309494372 is 27349490365912.

21956309494372 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×21956309494372² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129797578 + ... + 129966625.

It is an arithmetic number, because the mean of its divisors is an integer number (932813256564).

Almost surely, 2^{21956309494372} is an apocalyptic number.

21956309494372 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21956309494372 is an abundant number, since it is smaller than the sum of its proper divisors (22818726820700).

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

21956309494372 is a wasteful number, since it uses less digits than its factorization.

21956309494372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259764348 (or 259764346 counting only the distinct ones).

The product of its (nonzero) digits is 88179840, while the sum is 64.

The spelling of 21956309494372 in words is "twenty-one trillion, nine hundred fifty-six billion, three hundred nine million, four hundred ninety-four thousand, three hundred seventy-two".