31221213112908 has 480 divisors, whose sum is σ = 106105490247680. Its totient is φ = 7783222970880.

The previous prime is 31221213112897. The next prime is 31221213112909. The reversal of 31221213112908 is 80921131212213.

31221213112908 is a `hidden beast` number, since 3 + 12 + 21 + 21 + 311 + 290 + 8 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (31221213112909) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 38904978 + ... + 39699366.

Almost surely, 2^{31221213112908} 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 31221213112908, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53052745123840).

31221213112908 is an abundant number, since it is smaller than the sum of its proper divisors (74884277134772).

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

31221213112908 is a wasteful number, since it uses less digits than its factorization.

31221213112908 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794499 (or 794488 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 31221213112908 in words is "thirty-one trillion, two hundred twenty-one billion, two hundred thirteen million, one hundred twelve thousand, nine hundred eight".