31123012020 has 48 divisors (see below), whose sum is σ = 87268866048. Its totient is φ = 8287619200.

The previous prime is 31123011991. The next prime is 31123012031. The reversal of 31123012020 is 2021032113.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 327924 + ... + 412043.

It is an arithmetic number, because the mean of its divisors is an integer number (1818101376).

Almost surely, 2^31123012020 is an apocalyptic number.

31123012020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31123012020 is an abundant number, since it is smaller than the sum of its proper divisors (56145854028).

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

31123012020 is a wasteful number, since it uses less digits than its factorization.

31123012020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 740680 (or 740678 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 31123012020 its reverse (2021032113), we get a palindrome (33144044133).

The spelling of 31123012020 in words is "thirty-one billion, one hundred twenty-three million, twelve thousand, twenty".