623581 has 4 divisors (see below), whose sum is σ = 712672. Its totient is φ = 534492.

The previous prime is 623563. The next prime is 623591. The reversal of 623581 is 185326.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 623581 - 2¹³ = 615389 is a prime.

It is a super-2 number, since 2×623581² = 777706527122, which contains 22 as substring.

It is a Duffinian number.

It is a plaindrome in base 13 and base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (623521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44535 + ... + 44548.

It is an arithmetic number, because the mean of its divisors is an integer number (178168).

2⁶²³⁵⁸¹ is an apocalyptic number.

It is an amenable number.

623581 is a deficient number, since it is larger than the sum of its proper divisors (89091).

623581 is an equidigital number, since it uses as much as digits as its factorization.

623581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89090.

The product of its digits is 1440, while the sum is 25.

The square root of 623581 is about 789.6714506679. The cubic root of 623581 is about 85.4340428130.

The spelling of 623581 in words is "six hundred twenty-three thousand, five hundred eighty-one".