391641265 has 4 divisors (see below), whose sum is σ = 469969524. Its totient is φ = 313313008.

The previous prime is 391641253. The next prime is 391641269. The reversal of 391641265 is 562146193.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 74943649 + 316697616 = 8657^2 + 17796^2 .

It is a cyclic number.

It is not a de Polignac number, because 391641265 - 2¹⁷ = 391510193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (391641269) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39164122 + ... + 39164131.

It is an arithmetic number, because the mean of its divisors is an integer number (117492381).

Almost surely, 2^391641265 is an apocalyptic number.

It is an amenable number.

391641265 is a deficient number, since it is larger than the sum of its proper divisors (78328259).

391641265 is an equidigital number, since it uses as much as digits as its factorization.

391641265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78328258.

The product of its digits is 38880, while the sum is 37.

The square root of 391641265 is about 19789.9283727860. The cubic root of 391641265 is about 731.6378219912.

The spelling of 391641265 in words is "three hundred ninety-one million, six hundred forty-one thousand, two hundred sixty-five".