90909145 has 4 divisors (see below), whose sum is σ = 109090980. Its totient is φ = 72727312.

The previous prime is 90909127. The next prime is 90909157. The reversal of 90909145 is 54190909.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54190909 = 463 ⋅117043.

It can be written as a sum of positive squares in 2 ways, for example, as 61716736 + 29192409 = 7856^2 + 5403^2 .

It is a cyclic number.

It is not a de Polignac number, because 90909145 - 2¹⁹ = 90384857 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9090910 + ... + 9090919.

It is an arithmetic number, because the mean of its divisors is an integer number (27272745).

Almost surely, 2^90909145 is an apocalyptic number.

It is an amenable number.

90909145 is a deficient number, since it is larger than the sum of its proper divisors (18181835).

90909145 is a wasteful number, since it uses less digits than its factorization.

90909145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18181834.

The product of its (nonzero) digits is 14580, while the sum is 37.

The square root of 90909145 is about 9534.6287290067. The cubic root of 90909145 is about 449.6444022020.

The spelling of 90909145 in words is "ninety million, nine hundred nine thousand, one hundred forty-five".