626591 has 4 divisors (see below), whose sum is σ = 716112. Its totient is φ = 537072.

The previous prime is 626581. The next prime is 626597. The reversal of 626591 is 195626.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 195626 = 2 ⋅97813.

It is a cyclic number.

It is not a de Polignac number, because 626591 - 2¹⁸ = 364447 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (626597) 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 3 ways as a sum of consecutive naturals, for example, 44750 + ... + 44763.

It is an arithmetic number, because the mean of its divisors is an integer number (179028).

2⁶²⁶⁵⁹¹ is an apocalyptic number.

626591 is a deficient number, since it is larger than the sum of its proper divisors (89521).

626591 is an equidigital number, since it uses as much as digits as its factorization.

626591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89520.

The product of its digits is 3240, while the sum is 29.

The square root of 626591 is about 791.5750122383. The cubic root of 626591 is about 85.5712844404.

The spelling of 626591 in words is "six hundred twenty-six thousand, five hundred ninety-one".