399520131389 has 4 divisors (see below), whose sum is σ = 399560330460. Its totient is φ = 399479932320.

The previous prime is 399520131359. The next prime is 399520131419. The reversal of 399520131389 is 983131025993.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 983131025993 = 160243 ⋅6135251.

It is an interprime number because it is at equal distance from previous prime (399520131359) and next prime (399520131419).

It can be written as a sum of positive squares in 2 ways, for example, as 7716744025 + 391803387364 = 87845^2 + 625942^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-399520131389 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 399520131389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399520131359) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20084624 + ... + 20104505.

It is an arithmetic number, because the mean of its divisors is an integer number (99890082615).

Almost surely, 2^399520131389 is an apocalyptic number.

It is an amenable number.

399520131389 is a deficient number, since it is larger than the sum of its proper divisors (40199071).

399520131389 is an equidigital number, since it uses as much as digits as its factorization.

399520131389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40199070.

The product of its (nonzero) digits is 1574640, while the sum is 53.

The spelling of 399520131389 in words is "three hundred ninety-nine billion, five hundred twenty million, one hundred thirty-one thousand, three hundred eighty-nine".