90394581 has 4 divisors (see below), whose sum is σ = 120526112. Its totient is φ = 60263052.

The previous prime is 90394561. The next prime is 90394597. The reversal of 90394581 is 18549309.

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, and also an emirpimes, since its reverse is a distinct semiprime: 18549309 = 3 ⋅6183103.

It is not a de Polignac number, because 90394581 - 2⁶ = 90394517 is a prime.

It is a super-2 number, since 2×90394581² = 16342360548331122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90394501) 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, 15065761 + ... + 15065766.

It is an arithmetic number, because the mean of its divisors is an integer number (30131528).

Almost surely, 2^90394581 is an apocalyptic number.

It is an amenable number.

90394581 is a deficient number, since it is larger than the sum of its proper divisors (30131531).

90394581 is a wasteful number, since it uses less digits than its factorization.

90394581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30131530.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 90394581 is about 9507.6064811287. The cubic root of 90394581 is about 448.7944373455.

The spelling of 90394581 in words is "ninety million, three hundred ninety-four thousand, five hundred eighty-one".