669557 has 4 divisors (see below), whose sum is σ = 765216. Its totient is φ = 573900.

The previous prime is 669551. The next prime is 669577. The reversal of 669557 is 755966.

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 669557 - 2⁸ = 669301 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 669557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669551) 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, 47819 + ... + 47832.

It is an arithmetic number, because the mean of its divisors is an integer number (191304).

2⁶⁶⁹⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

669557 is a deficient number, since it is larger than the sum of its proper divisors (95659).

669557 is an equidigital number, since it uses as much as digits as its factorization.

669557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95658.

The product of its digits is 56700, while the sum is 38.

The square root of 669557 is about 818.2646271225. The cubic root of 669557 is about 87.4841114008.

The spelling of 669557 in words is "six hundred sixty-nine thousand, five hundred fifty-seven".