21131477618212 has 96 divisors (see below), whose sum is σ = 41911745863680. Its totient is φ = 9249264435840.

The previous prime is 21131477618197. The next prime is 21131477618231. The reversal of 21131477618212 is 21281677413112.

It is a Smith number, since the sum of its digits (46) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 172752489 + ... + 172874767.

It is an arithmetic number, because the mean of its divisors is an integer number (436580686080).

Almost surely, 2^{21131477618212} is an apocalyptic number.

It is an amenable number.

21131477618212 is a deficient number, since it is larger than the sum of its proper divisors (20780268245468).

21131477618212 is a wasteful number, since it uses less digits than its factorization.

21131477618212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123553 (or 123551 counting only the distinct ones).

The product of its digits is 225792, while the sum is 46.

The spelling of 21131477618212 in words is "twenty-one trillion, one hundred thirty-one billion, four hundred seventy-seven million, six hundred eighteen thousand, two hundred twelve".