90299021 has 4 divisors (see below), whose sum is σ = 90874332. Its totient is φ = 89723712.

The previous prime is 90299017. The next prime is 90299059. The reversal of 90299021 is 12099209.

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 52722121 + 37576900 = 7261^2 + 6130^2 .

It is a cyclic number.

It is not a de Polignac number, because 90299021 - 2² = 90299017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90299221) 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, 287420 + ... + 287733.

It is an arithmetic number, because the mean of its divisors is an integer number (22718583).

Almost surely, 2^90299021 is an apocalyptic number.

It is an amenable number.

90299021 is a deficient number, since it is larger than the sum of its proper divisors (575311).

90299021 is a wasteful number, since it uses less digits than its factorization.

90299021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575310.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 90299021 is about 9502.5797023756. The cubic root of 90299021 is about 448.6362349498.

The spelling of 90299021 in words is "ninety million, two hundred ninety-nine thousand, twenty-one".