399020937491 has 18 divisors (see below), whose sum is σ = 437489207028. Its totient is φ = 360927423360.

The previous prime is 399020937439. The next prime is 399020937533. The reversal of 399020937491 is 194739020993.

It is not a de Polignac number, because 399020937491 - 2¹⁴ = 399020921107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399020934491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 592898531 + ... + 592899203.

It is an arithmetic number, because the mean of its divisors is an integer number (24304955946).

Almost surely, 2^399020937491 is an apocalyptic number.

399020937491 is a deficient number, since it is larger than the sum of its proper divisors (38468269537).

399020937491 is an frugal number, since it uses more digits than its factorization.

399020937491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1923 (or 967 counting only the distinct ones).

The product of its (nonzero) digits is 3306744, while the sum is 56.

The spelling of 399020937491 in words is "three hundred ninety-nine billion, twenty million, nine hundred thirty-seven thousand, four hundred ninety-one".