390461987 has 4 divisors (see below), whose sum is σ = 390683496. Its totient is φ = 390240480.

The previous prime is 390461977. The next prime is 390462031. The reversal of 390461987 is 789164093.

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

It is a cyclic number.

It is not a de Polignac number, because 390461987 - 2²⁰ = 389413411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (390461917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108089 + ... + 111642.

It is an arithmetic number, because the mean of its divisors is an integer number (97670874).

Almost surely, 2^390461987 is an apocalyptic number.

390461987 is a deficient number, since it is larger than the sum of its proper divisors (221509).

390461987 is a wasteful number, since it uses less digits than its factorization.

390461987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221508.

The product of its (nonzero) digits is 326592, while the sum is 47.

The square root of 390461987 is about 19760.1110067732. Note that the first 3 decimals coincide. The cubic root of 390461987 is about 730.9027344522.

The spelling of 390461987 in words is "three hundred ninety million, four hundred sixty-one thousand, nine hundred eighty-seven".