557661 has 16 divisors (see below), whose sum is σ = 815360. Its totient is φ = 336960.

The previous prime is 557639. The next prime is 557663. The reversal of 557661 is 166755.

It is not a de Polignac number, because 557661 - 2⁷ = 557533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (557663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2991 + ... + 3171.

It is an arithmetic number, because the mean of its divisors is an integer number (50960).

2⁵⁵⁷⁶⁶¹ is an apocalyptic number.

It is an amenable number.

557661 is a deficient number, since it is larger than the sum of its proper divisors (257699).

557661 is a wasteful number, since it uses less digits than its factorization.

557661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 276.

The product of its digits is 6300, while the sum is 30.

The square root of 557661 is about 746.7670319450. The cubic root of 557661 is about 82.3107876805.

The spelling of 557661 in words is "five hundred fifty-seven thousand, six hundred sixty-one".