390878386 has 4 divisors (see below), whose sum is σ = 586317582. Its totient is φ = 195439192.

The previous prime is 390878381. The next prime is 390878417. The reversal of 390878386 is 683878093.

It is a happy number.

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., 390813361 + 65025 = 19769^2 + 255^2 .

It is not an unprimeable number, because it can be changed into a prime (390878381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97719595 + ... + 97719598.

Almost surely, 2^390878386 is an apocalyptic number.

390878386 is a deficient number, since it is larger than the sum of its proper divisors (195439196).

390878386 is a wasteful number, since it uses less digits than its factorization.

390878386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195439195.

The product of its (nonzero) digits is 1741824, while the sum is 52.

The square root of 390878386 is about 19770.6445519614. The cubic root of 390878386 is about 731.1624601566.

The spelling of 390878386 in words is "three hundred ninety million, eight hundred seventy-eight thousand, three hundred eighty-six".