581649 has 4 divisors (see below), whose sum is σ = 775536. Its totient is φ = 387764.

The previous prime is 581639. The next prime is 581657. The reversal of 581649 is 946185.

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 a cyclic number.

It is not a de Polignac number, because 581649 - 2⁵ = 581617 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (581639) 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, 96939 + ... + 96944.

It is an arithmetic number, because the mean of its divisors is an integer number (193884).

2⁵⁸¹⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

581649 is a deficient number, since it is larger than the sum of its proper divisors (193887).

581649 is a wasteful number, since it uses less digits than its factorization.

581649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193886.

The product of its digits is 8640, while the sum is 33.

The square root of 581649 is about 762.6591637160. The cubic root of 581649 is about 83.4744683914.

The spelling of 581649 in words is "five hundred eighty-one thousand, six hundred forty-nine".