31131020120100 has 36 divisors (see below), whose sum is σ = 90072418215024. Its totient is φ = 8301605365280.

The previous prime is 31131020120069. The next prime is 31131020120107. The reversal of 31131020120100 is 102102013113.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 31131020120100.

It is not an unprimeable number, because it can be changed into a prime (31131020120107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 51885033234 + ... + 51885033833.

It is an arithmetic number, because the mean of its divisors is an integer number (2502011617084).

Almost surely, 2^{31131020120100} is an apocalyptic number.

31131020120100 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31131020120100 is an abundant number, since it is smaller than the sum of its proper divisors (58941398094924).

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

31131020120100 is a wasteful number, since it uses less digits than its factorization.

31131020120100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103770067084 (or 103770067077 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 31131020120100 its reverse (102102013113), we get a palindrome (31233122133213).

The spelling of 31131020120100 in words is "thirty-one trillion, one hundred thirty-one billion, twenty million, one hundred twenty thousand, one hundred".