31021220313 has 6 divisors (see below), whose sum is σ = 44808429354. Its totient is φ = 20680813536.

The previous prime is 31021220297. The next prime is 31021220317. The reversal of 31021220313 is 31302212013.

31021220313 is a `hidden beast` number, since 310 + 21 + 2 + 20 + 313 = 666.

It can be written as a sum of positive squares in only one way, i.e., 16009334784 + 15011885529 = 126528^2 + 122523^2 .

It is not a de Polignac number, because 31021220313 - 2⁴ = 31021220297 is a prime.

It is a super-2 number, since 2×31021220313² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (31021220317) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1723401120 + ... + 1723401137.

It is an arithmetic number, because the mean of its divisors is an integer number (7468071559).

Almost surely, 2^31021220313 is an apocalyptic number.

It is an amenable number.

31021220313 is a deficient number, since it is larger than the sum of its proper divisors (13787209041).

31021220313 is a wasteful number, since it uses less digits than its factorization.

31021220313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3446802263 (or 3446802260 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 31021220313 its reverse (31302212013), we get a palindrome (62323432326).

The spelling of 31021220313 in words is "thirty-one billion, twenty-one million, two hundred twenty thousand, three hundred thirteen".