399926128987 has 16 divisors (see below), whose sum is σ = 527939154432. Its totient is φ = 293299528320.

The previous prime is 399926128969. The next prime is 399926129011. The reversal of 399926128987 is 789821629993.

It is a cyclic number.

It is not a de Polignac number, because 399926128987 - 2⁷ = 399926128859 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399926128957) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152758863 + ... + 152761480.

It is an arithmetic number, because the mean of its divisors is an integer number (32996197152).

Almost surely, 2^399926128987 is an apocalyptic number.

399926128987 is a deficient number, since it is larger than the sum of its proper divisors (128013025445).

399926128987 is a wasteful number, since it uses less digits than its factorization.

399926128987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305520378.

The product of its digits is 211631616, while the sum is 73.

The spelling of 399926128987 in words is "three hundred ninety-nine billion, nine hundred twenty-six million, one hundred twenty-eight thousand, nine hundred eighty-seven".