31122056820 has 48 divisors (see below), whose sum is σ = 88191673920. Its totient is φ = 8199223296.

The previous prime is 31122056761. The next prime is 31122056821. The reversal of 31122056820 is 2865022113.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31122056821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3119725 + ... + 3129684.

It is an arithmetic number, because the mean of its divisors is an integer number (1837326540).

Almost surely, 2^31122056820 is an apocalyptic number.

31122056820 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31122056820 is an abundant number, since it is smaller than the sum of its proper divisors (57069617100).

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

31122056820 is a wasteful number, since it uses less digits than its factorization.

31122056820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6249504 (or 6249502 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

Adding to 31122056820 its reverse (2865022113), we get a palindrome (33987078933).

The spelling of 31122056820 in words is "thirty-one billion, one hundred twenty-two million, fifty-six thousand, eight hundred twenty".