391328288 has 54 divisors (see below), whose sum is σ = 837362799. Its totient is φ = 179941632.

The previous prime is 391328257. The next prime is 391328299. The reversal of 391328288 is 882823193.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 6697744 + 384630544 = 2588^2 + 19612^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=13988.

It is a super-3 number, since 3×391328288³ (a number of 27 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1454618 + ... + 1454886.

Almost surely, 2^391328288 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 391328288

391328288 is an abundant number, since it is smaller than the sum of its proper divisors (446034511).

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

391328288 is an equidigital number, since it uses as much as digits as its factorization.

391328288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 574 (or 284 counting only the distinct ones).

The product of its digits is 165888, while the sum is 44.

The square root of 391328288 is about 19782.0193104749. The cubic root of 391328288 is about 731.4428758712.

Multiplying 391328288 by its product of digits (165888), we get a square (64916667039744 = 8057088²).

The spelling of 391328288 in words is "three hundred ninety-one million, three hundred twenty-eight thousand, two hundred eighty-eight".