31315216212 has 144 divisors (see below), whose sum is σ = 93100879872. Its totient is φ = 8689561920.

The previous prime is 31315216199. The next prime is 31315216253. The reversal of 31315216212 is 21261251313.

31315216212 is a `hidden beast` number, since 3 + 1 + 3 + 15 + 21 + 621 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1541473 + ... + 1561655.

It is an arithmetic number, because the mean of its divisors is an integer number (646533888).

Almost surely, 2^31315216212 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 31315216212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46550439936).

31315216212 is an abundant number, since it is smaller than the sum of its proper divisors (61785663660).

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

31315216212 is a wasteful number, since it uses less digits than its factorization.

31315216212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20378 (or 20373 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

Adding to 31315216212 its reverse (21261251313), we get a palindrome (52576467525).

The spelling of 31315216212 in words is "thirty-one billion, three hundred fifteen million, two hundred sixteen thousand, two hundred twelve".