90557 has 4 divisors (see below), whose sum is σ = 91356. Its totient is φ = 89760.

The previous prime is 90547. The next prime is 90583. The reversal of 90557 is 75509.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 63001 + 27556 = 251^2 + 166^2 .

It is a cyclic number.

It is not a de Polignac number, because 90557 - 2¹⁰ = 89533 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 (90527) 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, 194 + ... + 467.

It is an arithmetic number, because the mean of its divisors is an integer number (22839).

2⁹⁰⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

90557 is a deficient number, since it is larger than the sum of its proper divisors (799).

90557 is a wasteful number, since it uses less digits than its factorization.

90557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798.

The product of its (nonzero) digits is 1575, while the sum is 26.

The square root of 90557 is about 300.9269014229. The cubic root of 90557 is about 44.9063071184.

The spelling of 90557 in words is "ninety thousand, five hundred fifty-seven".