21107212171236 has 36 divisors (see below), whose sum is σ = 53872345205952. Its totient is φ = 6967429259184.

The previous prime is 21107212171223. The next prime is 21107212171247. The reversal of 21107212171236 is 63217121270112.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21107212171236.

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, 2846168376 + ... + 2846175791.

Almost surely, 2^{21107212171236} is an apocalyptic number.

It is an amenable number.

21107212171236 is an abundant number, since it is smaller than the sum of its proper divisors (32765133034716).

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

21107212171236 is a wasteful number, since it uses less digits than its factorization.

21107212171236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5692344280 (or 5692344275 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The spelling of 21107212171236 in words is "twenty-one trillion, one hundred seven billion, two hundred twelve million, one hundred seventy-one thousand, two hundred thirty-six".