391093890625 has 21 divisors (see below), whose sum is σ = 488958838903. Its totient is φ = 312812575000.

The previous prime is 391093890619. The next prime is 391093890653. The reversal of 391093890625 is 526098390193.

It is a happy number.

The square root of 391093890625 is 625375.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 3 ways, for example, as 342635793201 + 48458097424 = 585351^2 + 220132^2 .

It is not a de Polignac number, because 391093890625 - 2⁹ = 391093890113 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 78169374 + ... + 78174376.

Almost surely, 2^391093890625 is an apocalyptic number.

391093890625 is the 625375-th square number.

391093890625 is the 312688-th centered octagonal number.

It is an amenable number.

391093890625 is a deficient number, since it is larger than the sum of its proper divisors (97864948278).

391093890625 is an frugal number, since it uses more digits than its factorization.

391093890625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10036 (or 5008 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 55.

The spelling of 391093890625 in words is "three hundred ninety-one billion, ninety-three million, eight hundred ninety thousand, six hundred twenty-five".