90569 has 6 divisors (see below), whose sum is σ = 94794. Its totient is φ = 86480.

The previous prime is 90547. The next prime is 90583. The reversal of 90569 is 96509.

It can be written as a sum of positive squares in only one way, i.e., 55225 + 35344 = 235^2 + 188^2 .

It is not a de Polignac number, because 90569 - 2⁸ = 90313 is a prime.

It is a super-2 number, since 2×90569² = 16405487522, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90529) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1904 + ... + 1950.

It is an arithmetic number, because the mean of its divisors is an integer number (15799).

2⁹⁰⁵⁶⁹ is an apocalyptic number.

It is an amenable number.

90569 is a deficient number, since it is larger than the sum of its proper divisors (4225).

90569 is an equidigital number, since it uses as much as digits as its factorization.

90569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 29.

The square root of 90569 is about 300.9468391593. The cubic root of 90569 is about 44.9082905907.

The spelling of 90569 in words is "ninety thousand, five hundred sixty-nine".