404393978 has 16 divisors (see below), whose sum is σ = 609978600. Its totient is φ = 201071616.

The previous prime is 404393971. The next prime is 404393989. The reversal of 404393978 is 879393404.

It can be written as a sum of positive squares in 4 ways, for example, as 403326889 + 1067089 = 20083^2 + 1033^2 .

It is not an unprimeable number, because it can be changed into a prime (404393971) 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, 413426 + ... + 414402.

Almost surely, 2^404393978 is an apocalyptic number.

404393978 is a deficient number, since it is larger than the sum of its proper divisors (205584622).

404393978 is a wasteful number, since it uses less digits than its factorization.

404393978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1921.

The product of its (nonzero) digits is 653184, while the sum is 47.

The square root of 404393978 is about 20109.5494230975. The cubic root of 404393978 is about 739.4944062830.

The spelling of 404393978 in words is "four hundred four million, three hundred ninety-three thousand, nine hundred seventy-eight".