90209917 has 4 divisors (see below), whose sum is σ = 103097056. Its totient is φ = 77322780.

The previous prime is 90209909. The next prime is 90209927. The reversal of 90209917 is 71990209.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71990209 = 29 ⋅2482421.

It is a cyclic number.

It is not a de Polignac number, because 90209917 - 2³ = 90209909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90209927) 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, 6443559 + ... + 6443572.

It is an arithmetic number, because the mean of its divisors is an integer number (25774264).

Almost surely, 2^90209917 is an apocalyptic number.

It is an amenable number.

90209917 is a deficient number, since it is larger than the sum of its proper divisors (12887139).

90209917 is a wasteful number, since it uses less digits than its factorization.

90209917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12887138.

The product of its (nonzero) digits is 10206, while the sum is 37.

The square root of 90209917 is about 9497.8901341298. The cubic root of 90209917 is about 448.4886200639.

The spelling of 90209917 in words is "ninety million, two hundred nine thousand, nine hundred seventeen".