399911856878 has 16 divisors (see below), whose sum is σ = 600272830080. Its totient is φ = 199820965176.

The previous prime is 399911856871. The next prime is 399911856887. The reversal of 399911856878 is 878658119993.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (399911856871) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20601125 + ... + 20620527.

It is an arithmetic number, because the mean of its divisors is an integer number (37517051880).

Almost surely, 2^399911856878 is an apocalyptic number.

399911856878 is a deficient number, since it is larger than the sum of its proper divisors (200360973202).

399911856878 is a wasteful number, since it uses less digits than its factorization.

399911856878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25831.

The product of its digits is 235146240, while the sum is 74.

The spelling of 399911856878 in words is "three hundred ninety-nine billion, nine hundred eleven million, eight hundred fifty-six thousand, eight hundred seventy-eight".