31212213312 has 56 divisors (see below), whose sum is σ = 94379791936. Its totient is φ = 8917774848.

The previous prime is 31212213289. The next prime is 31212213323. The reversal of 31212213312 is 21331221213.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11610343 + ... + 11613030.

Almost surely, 2^31212213312 is an apocalyptic number.

31212213312 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

31212213312 is an abundant number, since it is smaller than the sum of its proper divisors (63167578624).

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

31212213312 is a wasteful number, since it uses less digits than its factorization.

31212213312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23223395 (or 23223385 counting only the distinct ones).

The product of its digits is 432, while the sum is 21.

Adding to 31212213312 its reverse (21331221213), we get a palindrome (52543434525).

The spelling of 31212213312 in words is "thirty-one billion, two hundred twelve million, two hundred thirteen thousand, three hundred twelve".