391018442 has 32 divisors (see below), whose sum is σ = 643178880. Its totient is φ = 177629760.

The previous prime is 391018421. The next prime is 391018477. The reversal of 391018442 is 244810193.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 391018399 and 391018408.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97868 + ... + 101784.

It is an arithmetic number, because the mean of its divisors is an integer number (20099340).

Almost surely, 2^391018442 is an apocalyptic number.

391018442 is a deficient number, since it is larger than the sum of its proper divisors (252160438).

391018442 is a wasteful number, since it uses less digits than its factorization.

391018442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4046.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 391018442 is about 19774.1862538007. The cubic root of 391018442 is about 731.2497775634.

The spelling of 391018442 in words is "three hundred ninety-one million, eighteen thousand, four hundred forty-two".