390338978 has 4 divisors (see below), whose sum is σ = 585508470. Its totient is φ = 195169488.

The previous prime is 390338941. The next prime is 390338999. The reversal of 390338978 is 879833093.

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

It can be written as a sum of positive squares in only one way, i.e., 258019969 + 132319009 = 16063^2 + 11503^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97584743 + ... + 97584746.

Almost surely, 2^390338978 is an apocalyptic number.

390338978 is a deficient number, since it is larger than the sum of its proper divisors (195169492).

390338978 is a wasteful number, since it uses less digits than its factorization.

390338978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195169491.

The product of its (nonzero) digits is 979776, while the sum is 50.

The square root of 390338978 is about 19756.9982031684. The cubic root of 390338978 is about 730.8259731964.

The spelling of 390338978 in words is "three hundred ninety million, three hundred thirty-eight thousand, nine hundred seventy-eight".