391298320 has 120 divisors (see below), whose sum is σ = 1066264344. Its totient is φ = 133152768.

The previous prime is 391298279. The next prime is 391298329. The reversal of 391298320 is 23892193.

It can be written as a sum of positive squares in 4 ways, for example, as 244985104 + 146313216 = 15652^2 + 12096^2 .

It is a super-2 number, since 2×391298320² = 306228750469644800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 391298320.

It is not an unprimeable number, because it can be changed into a prime (391298329) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 677872 + ... + 678448.

Almost surely, 2^391298320 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 391298320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (533132172).

391298320 is an abundant number, since it is smaller than the sum of its proper divisors (674966024).

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

391298320 is a wasteful number, since it uses less digits than its factorization.

391298320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777 (or 764 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 391298320 is about 19781.2618404388. The cubic root of 391298320 is about 731.4242040464.

It can be divided in two parts, 3912983 and 20, that added together give a triangular number (3913003 = T₂₇₉₇).

The spelling of 391298320 in words is "three hundred ninety-one million, two hundred ninety-eight thousand, three hundred twenty".