399129236887 has 4 divisors (see below), whose sum is σ = 399142045576. Its totient is φ = 399116428200.

The previous prime is 399129236819. The next prime is 399129236927. The reversal of 399129236887 is 788632921993.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 399129236887 - 2¹⁹ = 399128712599 is a prime.

It is a super-2 number, since 2×399129236887² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399129236687) 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, 6357489 + ... + 6419962.

It is an arithmetic number, because the mean of its divisors is an integer number (99785511394).

Almost surely, 2^399129236887 is an apocalyptic number.

399129236887 is a deficient number, since it is larger than the sum of its proper divisors (12808689).

399129236887 is a wasteful number, since it uses less digits than its factorization.

399129236887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12808688.

The product of its digits is 70543872, while the sum is 67.

The spelling of 399129236887 in words is "three hundred ninety-nine billion, one hundred twenty-nine million, two hundred thirty-six thousand, eight hundred eighty-seven".