31511212112 has 20 divisors (see below), whose sum is σ = 64266288480. Its totient is φ = 14926363488.

The previous prime is 31511212079. The next prime is 31511212147. The reversal of 31511212112 is 21121211513.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51827348 + ... + 51827955.

It is an arithmetic number, because the mean of its divisors is an integer number (3213314424).

Almost surely, 2^31511212112 is an apocalyptic number.

It is an amenable number.

31511212112 is an abundant number, since it is smaller than the sum of its proper divisors (32755076368).

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

31511212112 is a wasteful number, since it uses less digits than its factorization.

31511212112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103655330 (or 103655324 counting only the distinct ones).

The product of its digits is 120, while the sum is 20.

Adding to 31511212112 its reverse (21121211513), we get a palindrome (52632423625).

The spelling of 31511212112 in words is "thirty-one billion, five hundred eleven million, two hundred twelve thousand, one hundred twelve".