31123203012 has 72 divisors (see below), whose sum is σ = 87033465792. Its totient is φ = 9298430400.

The previous prime is 31123202989. The next prime is 31123203029. The reversal of 31123203012 is 21030232113.

31123203012 is a `hidden beast` number, since 31 + 12 + 320 + 301 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

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 23 ways as a sum of consecutive naturals, for example, 525363 + ... + 581594.

It is an arithmetic number, because the mean of its divisors is an integer number (1208798136).

Almost surely, 2^31123203012 is an apocalyptic number.

It is an amenable number.

31123203012 is an abundant number, since it is smaller than the sum of its proper divisors (55910262780).

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

31123203012 is a wasteful number, since it uses less digits than its factorization.

31123203012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1107049 (or 1107044 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31123203012 its reverse (21030232113), we get a palindrome (52153435125).

The spelling of 31123203012 in words is "thirty-one billion, one hundred twenty-three million, two hundred three thousand, twelve".