90005281 has 4 divisors (see below), whose sum is σ = 90714112. Its totient is φ = 89296452.

The previous prime is 90005263. The next prime is 90005287. The reversal of 90005281 is 18250009.

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: 18250009 = 821 ⋅22229.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90005281 is a prime.

It is a super-2 number, since 2×90005281² = 16201901215777922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90005287) 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, 354225 + ... + 354478.

It is an arithmetic number, because the mean of its divisors is an integer number (22678528).

Almost surely, 2^90005281 is an apocalyptic number.

It is an amenable number.

90005281 is a deficient number, since it is larger than the sum of its proper divisors (708831).

90005281 is a wasteful number, since it uses less digits than its factorization.

90005281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 708830.

The product of its (nonzero) digits is 720, while the sum is 25.

The square root of 90005281 is about 9487.1113095610. Note that the first 3 decimals coincide. The cubic root of 90005281 is about 448.1492397800.

The spelling of 90005281 in words is "ninety million, five thousand, two hundred eighty-one".