391983425 has 6 divisors (see below), whose sum is σ = 486059478. Its totient is φ = 313586720.

The previous prime is 391983421. The next prime is 391983481. The reversal of 391983425 is 524389193.

It can be written as a sum of positive squares in 3 ways, for example, as 97792321 + 294191104 = 9889^2 + 17152^2 .

It is not a de Polignac number, because 391983425 - 2² = 391983421 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391983421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7839644 + ... + 7839693.

It is an arithmetic number, because the mean of its divisors is an integer number (81009913).

Almost surely, 2^391983425 is an apocalyptic number.

It is an amenable number.

391983425 is a deficient number, since it is larger than the sum of its proper divisors (94076053).

391983425 is a wasteful number, since it uses less digits than its factorization.

391983425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15679347 (or 15679342 counting only the distinct ones).

The product of its digits is 233280, while the sum is 44.

The square root of 391983425 is about 19798.5712868378. The cubic root of 391983425 is about 731.8508267245.

The spelling of 391983425 in words is "three hundred ninety-one million, nine hundred eighty-three thousand, four hundred twenty-five".