31138879 has 2 divisors, whose sum is σ = 31138880. Its totient is φ = 31138878.

The previous prime is 31138873. The next prime is 31138889. The reversal of 31138879 is 97883113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31138879 - 2³ = 31138871 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31138871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15569439 + 15569440.

It is an arithmetic number, because the mean of its divisors is an integer number (15569440).

Almost surely, 2^31138879 is an apocalyptic number.

31138879 is a deficient number, since it is larger than the sum of its proper divisors (1).

31138879 is an equidigital number, since it uses as much as digits as its factorization.

31138879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 40.

The square root of 31138879 is about 5580.2221281953. Note that the first 3 decimals coincide. The cubic root of 31138879 is about 314.6064759120.

The spelling of 31138879 in words is "thirty-one million, one hundred thirty-eight thousand, eight hundred seventy-nine".