31311312221020 has 48 divisors (see below), whose sum is σ = 70822960947648. Its totient is φ = 11559267394560.

The previous prime is 31311312220997. The next prime is 31311312221029. The reversal of 31311312221020 is 2012221311313.

It is a junction number, because it is equal to n+sod(n) for n = 31311312220982 and 31311312221000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31311312221029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7900269 + ... + 11181988.

It is an arithmetic number, because the mean of its divisors is an integer number (1475478353076).

Almost surely, 2^{31311312221020} is an apocalyptic number.

It is an amenable number.

31311312221020 is an abundant number, since it is smaller than the sum of its proper divisors (39511648726628).

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

31311312221020 is a wasteful number, since it uses less digits than its factorization.

31311312221020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19088590 (or 19088588 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 31311312221020 its reverse (2012221311313), we get a palindrome (33323533532333).

The spelling of 31311312221020 in words is "thirty-one trillion, three hundred eleven billion, three hundred twelve million, two hundred twenty-one thousand, twenty".