31307620221 has 6 divisors (see below), whose sum is σ = 45222118110. Its totient is φ = 20871746808.

The previous prime is 31307620207. The next prime is 31307620237. The reversal of 31307620221 is 12202670313.

31307620221 is a `hidden beast` number, since 3 + 1 + 30 + 7 + 620 + 2 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 30584763225 + 722856996 = 174885^2 + 26886^2 .

It is not a de Polignac number, because 31307620221 - 2⁹ = 31307619709 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31307620261) 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, 1739312226 + ... + 1739312243.

It is an arithmetic number, because the mean of its divisors is an integer number (7537019685).

Almost surely, 2^31307620221 is an apocalyptic number.

It is an amenable number.

31307620221 is a deficient number, since it is larger than the sum of its proper divisors (13914497889).

31307620221 is a wasteful number, since it uses less digits than its factorization.

31307620221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3478624475 (or 3478624472 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The spelling of 31307620221 in words is "thirty-one billion, three hundred seven million, six hundred twenty thousand, two hundred twenty-one".