90256581 has 6 divisors (see below), whose sum is σ = 130370630. Its totient is φ = 60171048.

The previous prime is 90256561. The next prime is 90256589. The reversal of 90256581 is 18565209.

It is a happy number.

90256581 is a `hidden beast` number, since 90 + 2 + 565 + 8 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 87048900 + 3207681 = 9330^2 + 1791^2 .

It is not a de Polignac number, because 90256581 - 2⁹ = 90256069 is a prime.

It is a super-2 number, since 2×90256581² = 16292500827619122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90256589) 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, 5014246 + ... + 5014263.

Almost surely, 2^90256581 is an apocalyptic number.

It is an amenable number.

90256581 is a deficient number, since it is larger than the sum of its proper divisors (40114049).

90256581 is a wasteful number, since it uses less digits than its factorization.

90256581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10028515 (or 10028512 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 36.

The square root of 90256581 is about 9500.3463621070. The cubic root of 90256581 is about 448.5659384863.

The spelling of 90256581 in words is "ninety million, two hundred fifty-six thousand, five hundred eighty-one".