21261356255116 has 12 divisors (see below), whose sum is σ = 37208650981320. Its totient is φ = 10630313117600.

The previous prime is 21261356255089. The next prime is 21261356255177. The reversal of 21261356255116 is 61155265316212.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91121410 + ... + 91354441.

It is an arithmetic number, because the mean of its divisors is an integer number (3100720915110).

Almost surely, 2^{21261356255116} is an apocalyptic number.

It is an amenable number.

21261356255116 is a deficient number, since it is larger than the sum of its proper divisors (15947294726204).

21261356255116 is a wasteful number, since it uses less digits than its factorization.

21261356255116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182504984 (or 182504982 counting only the distinct ones).

The product of its digits is 648000, while the sum is 46.

The spelling of 21261356255116 in words is "twenty-one trillion, two hundred sixty-one billion, three hundred fifty-six million, two hundred fifty-five thousand, one hundred sixteen".