31123131102 has 48 divisors (see below), whose sum is σ = 77621281920. Its totient is φ = 8828344656.

The previous prime is 31123131059. The next prime is 31123131103. The reversal of 31123131102 is 20113132113.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31123131103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 871008 + ... + 906035.

It is an arithmetic number, because the mean of its divisors is an integer number (1617110040).

Almost surely, 2^31123131102 is an apocalyptic number.

31123131102 is an abundant number, since it is smaller than the sum of its proper divisors (46498150818).

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

31123131102 is a wasteful number, since it uses less digits than its factorization.

31123131102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1777197 (or 1777194 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 31123131102 its reverse (20113132113), we get a palindrome (51236263215).

The spelling of 31123131102 in words is "thirty-one billion, one hundred twenty-three million, one hundred thirty-one thousand, one hundred two".