21170399640912 has 240 divisors, whose sum is σ = 66230603112960. Its totient is φ = 6273455505408.

The previous prime is 21170399640889. The next prime is 21170399640913. The reversal of 21170399640912 is 21904699307112.

21170399640912 is a `hidden beast` number, since 2 + 117 + 0 + 39 + 96 + 409 + 1 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170399640913) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14999233 + ... + 16349855.

It is an arithmetic number, because the mean of its divisors is an integer number (275960846304).

Almost surely, 2^{21170399640912} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21170399640912, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33115301556480).

21170399640912 is an abundant number, since it is smaller than the sum of its proper divisors (45060203472048).

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

21170399640912 is a wasteful number, since it uses less digits than its factorization.

21170399640912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1351010 (or 1351001 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 21170399640912 in words is "twenty-one trillion, one hundred seventy billion, three hundred ninety-nine million, six hundred forty thousand, nine hundred twelve".