90240581 has 4 divisors (see below), whose sum is σ = 90499500. Its totient is φ = 89981664.

The previous prime is 90240511. The next prime is 90240583. The reversal of 90240581 is 18504209.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43112356 + 47128225 = 6566^2 + 6865^2 .

It is a cyclic number.

It is not a de Polignac number, because 90240581 - 2¹⁸ = 89978437 is a prime.

It is a super-2 number, since 2×90240581² = 16286724918435122, 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 (90240583) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128936 + ... + 129633.

It is an arithmetic number, because the mean of its divisors is an integer number (22624875).

Almost surely, 2^90240581 is an apocalyptic number.

It is an amenable number.

90240581 is a deficient number, since it is larger than the sum of its proper divisors (258919).

90240581 is a wasteful number, since it uses less digits than its factorization.

90240581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258918.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 90240581 is about 9499.5042502227. The cubic root of 90240581 is about 448.5394308009.

The spelling of 90240581 in words is "ninety million, two hundred forty thousand, five hundred eighty-one".