90506491 has 4 divisors (see below), whose sum is σ = 90626184. Its totient is φ = 90386800.

The previous prime is 90506473. The next prime is 90506501. The reversal of 90506491 is 19460509.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19460509 = 241 ⋅80749.

It is a cyclic number.

It is not a de Polignac number, because 90506491 - 2⁹ = 90505979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90506441) 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, 58705 + ... + 60226.

It is an arithmetic number, because the mean of its divisors is an integer number (22656546).

Almost surely, 2^90506491 is an apocalyptic number.

90506491 is a deficient number, since it is larger than the sum of its proper divisors (119693).

90506491 is a wasteful number, since it uses less digits than its factorization.

90506491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119692.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 90506491 is about 9513.4899484889. The cubic root of 90506491 is about 448.9795659704.

The spelling of 90506491 in words is "ninety million, five hundred six thousand, four hundred ninety-one".