391408425 has 36 divisors (see below), whose sum is σ = 742301820. Its totient is φ = 196469760.

The previous prime is 391408399. The next prime is 391408429. The reversal of 391408425 is 524804193.

It can be written as a sum of positive squares in 6 ways, for example, as 6110784 + 385297641 = 2472^2 + 19629^2 .

It is not a de Polignac number, because 391408425 - 2⁵ = 391408393 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 391408425.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (391408429) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 47340 + ... + 54989.

It is an arithmetic number, because the mean of its divisors is an integer number (20619495).

Almost surely, 2^391408425 is an apocalyptic number.

It is an amenable number.

391408425 is a deficient number, since it is larger than the sum of its proper divisors (350893395).

391408425 is a wasteful number, since it uses less digits than its factorization.

391408425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102362 (or 102354 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 391408425 is about 19784.0447077942. The cubic root of 391408425 is about 731.4928012483.

The spelling of 391408425 in words is "three hundred ninety-one million, four hundred eight thousand, four hundred twenty-five".