31313220420 has 24 divisors (see below), whose sum is σ = 87677017344. Its totient is φ = 8350192096.

The previous prime is 31313220401. The next prime is 31313220443. The reversal of 31313220420 is 2402231313.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260943444 + ... + 260943563.

It is an arithmetic number, because the mean of its divisors is an integer number (3653209056).

Almost surely, 2^31313220420 is an apocalyptic number.

31313220420 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

31313220420 is an abundant number, since it is smaller than the sum of its proper divisors (56363796924).

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

31313220420 is a wasteful number, since it uses less digits than its factorization.

31313220420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521887019 (or 521887017 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 31313220420 its reverse (2402231313), we get a palindrome (33715451733).

The spelling of 31313220420 in words is "thirty-one billion, three hundred thirteen million, two hundred twenty thousand, four hundred twenty".