90971917 has 4 divisors (see below), whose sum is σ = 91480320. Its totient is φ = 90463516.

The previous prime is 90971899. The next prime is 90971921. The reversal of 90971917 is 71917909.

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: 71917909 = 7 ⋅10273987.

It is a cyclic number.

It is not a de Polignac number, because 90971917 - 2¹¹ = 90969869 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 (90971977) 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, 253933 + ... + 254290.

It is an arithmetic number, because the mean of its divisors is an integer number (22870080).

Almost surely, 2^90971917 is an apocalyptic number.

It is an amenable number.

90971917 is a deficient number, since it is larger than the sum of its proper divisors (508403).

90971917 is a wasteful number, since it uses less digits than its factorization.

90971917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508402.

The product of its (nonzero) digits is 35721, while the sum is 43.

The square root of 90971917 is about 9537.9199514360. The cubic root of 90971917 is about 449.7478702837.

The spelling of 90971917 in words is "ninety million, nine hundred seventy-one thousand, nine hundred seventeen".