31427220857 has 4 divisors (see below), whose sum is σ = 31431937140. Its totient is φ = 31422504576.

The previous prime is 31427220841. The next prime is 31427220863. The reversal of 31427220857 is 75802272413.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 780867136 + 30646353721 = 27944^2 + 175061^2 .

It is a cyclic number.

It is not a de Polignac number, because 31427220857 - 2⁴ = 31427220841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31427220257) 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 3 ways as a sum of consecutive naturals, for example, 2348132 + ... + 2361477.

It is an arithmetic number, because the mean of its divisors is an integer number (7857984285).

Almost surely, 2^31427220857 is an apocalyptic number.

It is an amenable number.

31427220857 is a deficient number, since it is larger than the sum of its proper divisors (4716283).

31427220857 is an equidigital number, since it uses as much as digits as its factorization.

31427220857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4716282.

The product of its (nonzero) digits is 188160, while the sum is 41.

The spelling of 31427220857 in words is "thirty-one billion, four hundred twenty-seven million, two hundred twenty thousand, eight hundred fifty-seven".