391025 has 6 divisors (see below), whose sum is σ = 484902. Its totient is φ = 312800.

The previous prime is 391021. The next prime is 391031. The reversal of 391025 is 520193.

It can be written as a sum of positive squares in 3 ways, for example, as 128881 + 262144 = 359^2 + 512^2 .

It is not a de Polignac number, because 391025 - 2² = 391021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 390988 and 391006.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 391025.

It is not an unprimeable number, because it can be changed into a prime (391021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7796 + ... + 7845.

It is an arithmetic number, because the mean of its divisors is an integer number (80817).

2³⁹¹⁰²⁵ is an apocalyptic number.

It is an amenable number.

391025 is a deficient number, since it is larger than the sum of its proper divisors (93877).

391025 is a wasteful number, since it uses less digits than its factorization.

391025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15651 (or 15646 counting only the distinct ones).

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 391025 is about 625.3199181219. The cubic root of 391025 is about 73.1253865614.

The spelling of 391025 in words is "three hundred ninety-one thousand, twenty-five".