393990638 has 8 divisors (see below), whose sum is σ = 591251232. Its totient is φ = 196906896.

The previous prime is 393990601. The next prime is 393990677. The reversal of 393990638 is 836099393.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38495 + ... + 47642.

It is an arithmetic number, because the mean of its divisors is an integer number (73906404).

Almost surely, 2^393990638 is an apocalyptic number.

393990638 is a deficient number, since it is larger than the sum of its proper divisors (197260594).

393990638 is a wasteful number, since it uses less digits than its factorization.

393990638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88426.

The product of its (nonzero) digits is 944784, while the sum is 50.

The square root of 393990638 is about 19849.1974145052. The cubic root of 393990638 is about 733.0978864440.

The spelling of 393990638 in words is "three hundred ninety-three million, nine hundred ninety thousand, six hundred thirty-eight".