390369978 has 12 divisors (see below), whose sum is σ = 845801658. Its totient is φ = 130123320.

The previous prime is 390369923. The next prime is 390369989. The reversal of 390369978 is 879963093.

390369978 is nontrivially palindromic in base 8.

It can be written as a sum of positive squares in only one way, i.e., 288218529 + 102151449 = 16977^2 + 10107^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10843593 + ... + 10843628.

Almost surely, 2^390369978 is an apocalyptic number.

390369978 is an abundant number, since it is smaller than the sum of its proper divisors (455431680).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

390369978 is a wasteful number, since it uses less digits than its factorization.

390369978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21687229 (or 21687226 counting only the distinct ones).

The product of its (nonzero) digits is 2204496, while the sum is 54.

The square root of 390369978 is about 19757.7827197284. The cubic root of 390369978 is about 730.8453196334.

The spelling of 390369978 in words is "three hundred ninety million, three hundred sixty-nine thousand, nine hundred seventy-eight".