90509091 has 4 divisors (see below), whose sum is σ = 120678792. Its totient is φ = 60339392.

The previous prime is 90509059. The next prime is 90509113. The reversal of 90509091 is 19090509.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19090509 = 3 ⋅6363503.

It is a cyclic number.

It is not a de Polignac number, because 90509091 - 2⁵ = 90509059 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90509011) 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, 15084846 + ... + 15084851.

It is an arithmetic number, because the mean of its divisors is an integer number (30169698).

Almost surely, 2^90509091 is an apocalyptic number.

90509091 is a deficient number, since it is larger than the sum of its proper divisors (30169701).

90509091 is a wasteful number, since it uses less digits than its factorization.

90509091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30169700.

The product of its (nonzero) digits is 3645, while the sum is 33.

The square root of 90509091 is about 9513.6265955733. The cubic root of 90509091 is about 448.9838652410.

The spelling of 90509091 in words is "ninety million, five hundred nine thousand, ninety-one".