396491591 has 4 divisors (see below), whose sum is σ = 396723432. Its totient is φ = 396259752.

The previous prime is 396491573. The next prime is 396491597. The reversal of 396491591 is 195194693.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 396491591 - 2¹⁸ = 396229447 is a prime.

It is a super-2 number, since 2×396491591² = 314411163467422562, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (396491597) 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, 113336 + ... + 116781.

It is an arithmetic number, because the mean of its divisors is an integer number (99180858).

Almost surely, 2^396491591 is an apocalyptic number.

396491591 is a deficient number, since it is larger than the sum of its proper divisors (231841).

396491591 is a wasteful number, since it uses less digits than its factorization.

396491591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231840.

The product of its digits is 262440, while the sum is 47.

The square root of 396491591 is about 19912.0965998059. The cubic root of 396491591 is about 734.6457891887.

The spelling of 396491591 in words is "three hundred ninety-six million, four hundred ninety-one thousand, five hundred ninety-one".