31132121020 has 96 divisors (see below), whose sum is σ = 87779575296. Its totient is φ = 8957088000.

The previous prime is 31132121011. The next prime is 31132121023. The reversal of 31132121020 is 2012123113.

It is a junction number, because it is equal to n+sod(n) for n = 31132120985 and 31132121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31132121023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 757506 + ... + 797545.

It is an arithmetic number, because the mean of its divisors is an integer number (914370576).

Almost surely, 2^31132121020 is an apocalyptic number.

It is an amenable number.

31132121020 is an abundant number, since it is smaller than the sum of its proper divisors (56647454276).

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

31132121020 is a wasteful number, since it uses less digits than its factorization.

31132121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1555091 (or 1555089 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 31132121020 its reverse (2012123113), we get a palindrome (33144244133).

The spelling of 31132121020 in words is "thirty-one billion, one hundred thirty-two million, one hundred twenty-one thousand, twenty".