399240056731 has 2 divisors, whose sum is σ = 399240056732. Its totient is φ = 399240056730.

The previous prime is 399240056713. The next prime is 399240056767. The reversal of 399240056731 is 137650042993.

Together with previous prime (399240056713) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 399240056731 - 2¹³ = 399240048539 is a prime.

It is a super-2 number, since 2×399240056731² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (399240057731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199620028365 + 199620028366.

It is an arithmetic number, because the mean of its divisors is an integer number (199620028366).

Almost surely, 2^399240056731 is an apocalyptic number.

399240056731 is a deficient number, since it is larger than the sum of its proper divisors (1).

399240056731 is an equidigital number, since it uses as much as digits as its factorization.

399240056731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 49.

The spelling of 399240056731 in words is "three hundred ninety-nine billion, two hundred forty million, fifty-six thousand, seven hundred thirty-one".