390664987 has 8 divisors (see below), whose sum is σ = 401011776. Its totient is φ = 380403072.

The previous prime is 390664973. The next prime is 390664993. The reversal of 390664987 is 789466093.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 390664987 - 2²³ = 382276379 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390664927) 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, 11838 + ... + 30355.

It is an arithmetic number, because the mean of its divisors is an integer number (50126472).

Almost surely, 2^390664987 is an apocalyptic number.

390664987 is a deficient number, since it is larger than the sum of its proper divisors (10346789).

390664987 is a wasteful number, since it uses less digits than its factorization.

390664987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42437.

The product of its (nonzero) digits is 1959552, while the sum is 52.

The square root of 390664987 is about 19765.2469501395. The cubic root of 390664987 is about 731.0293772109.

The spelling of 390664987 in words is "three hundred ninety million, six hundred sixty-four thousand, nine hundred eighty-seven".