315840638 has 4 divisors (see below), whose sum is σ = 473760960. Its totient is φ = 157920318.

The previous prime is 315840631. The next prime is 315840641. The reversal of 315840638 is 836048513.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836048513 = 2939 ⋅284467.

It is a super-2 number, since 2×315840638² = 199510617224494088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315840631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78960158 + ... + 78960161.

It is an arithmetic number, because the mean of its divisors is an integer number (118440240).

Almost surely, 2^315840638 is an apocalyptic number.

315840638 is a deficient number, since it is larger than the sum of its proper divisors (157920322).

315840638 is a wasteful number, since it uses less digits than its factorization.

315840638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157920321.

The product of its (nonzero) digits is 69120, while the sum is 38.

The square root of 315840638 is about 17771.9058629062. The cubic root of 315840638 is about 681.0139415223.

The spelling of 315840638 in words is "three hundred fifteen million, eight hundred forty thousand, six hundred thirty-eight".