391915842 has 16 divisors (see below), whose sum is σ = 784449792. Its totient is φ = 130535600.

The previous prime is 391915829. The next prime is 391915847. The reversal of 391915842 is 248519193.

It is a junction number, because it is equal to n+sod(n) for n = 391915794 and 391915803.

It is not an unprimeable number, because it can be changed into a prime (391915847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17298 + ... + 32909.

It is an arithmetic number, because the mean of its divisors is an integer number (49028112).

Almost surely, 2^391915842 is an apocalyptic number.

391915842 is an abundant number, since it is smaller than the sum of its proper divisors (392533950).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

391915842 is a wasteful number, since it uses less digits than its factorization.

391915842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51513.

The product of its digits is 77760, while the sum is 42.

The square root of 391915842 is about 19796.8644486949. The cubic root of 391915842 is about 731.8087641320.

The spelling of 391915842 in words is "three hundred ninety-one million, nine hundred fifteen thousand, eight hundred forty-two".