31138919723 has 2 divisors, whose sum is σ = 31138919724. Its totient is φ = 31138919722.

The previous prime is 31138919717. The next prime is 31138919753. The reversal of 31138919723 is 32791983113.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31138919723 - 2¹⁴ = 31138903339 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (31138919753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15569459861 + 15569459862.

It is an arithmetic number, because the mean of its divisors is an integer number (15569459862).

Almost surely, 2^31138919723 is an apocalyptic number.

31138919723 is a deficient number, since it is larger than the sum of its proper divisors (1).

31138919723 is an equidigital number, since it uses as much as digits as its factorization.

31138919723 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 47.

The spelling of 31138919723 in words is "thirty-one billion, one hundred thirty-eight million, nine hundred nineteen thousand, seven hundred twenty-three".