31213121010 has 32 divisors (see below), whose sum is σ = 74999373120. Its totient is φ = 8313734208.

The previous prime is 31213121003. The next prime is 31213121021. The reversal of 31213121010 is 1012131213.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 584280 + ... + 635459.

It is an arithmetic number, because the mean of its divisors is an integer number (2343730410).

Almost surely, 2^31213121010 is an apocalyptic number.

31213121010 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

31213121010 is an abundant number, since it is smaller than the sum of its proper divisors (43786252110).

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

31213121010 is a wasteful number, since it uses less digits than its factorization.

31213121010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1220602.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 31213121010 its reverse (1012131213), we get a palindrome (32225252223).

The spelling of 31213121010 in words is "thirty-one billion, two hundred thirteen million, one hundred twenty-one thousand, ten".