391820268 has 72 divisors (see below), whose sum is σ = 1073105712. Its totient is φ = 110939136.

The previous prime is 391820251. The next prime is 391820279. The reversal of 391820268 is 862028193.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63496 + ... + 69392.

It is an arithmetic number, because the mean of its divisors is an integer number (14904246).

Almost surely, 2^391820268 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391820268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (536552856).

391820268 is an abundant number, since it is smaller than the sum of its proper divisors (681285444).

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

391820268 is a wasteful number, since it uses less digits than its factorization.

391820268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6031 (or 6022 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 39.

The square root of 391820268 is about 19794.4504344021. The cubic root of 391820268 is about 731.7492721275.

The spelling of 391820268 in words is "three hundred ninety-one million, eight hundred twenty thousand, two hundred sixty-eight".