90154971917 has 4 divisors (see below), whose sum is σ = 90997541856. Its totient is φ = 89312401980.

The previous prime is 90154971887. The next prime is 90154971941. The reversal of 90154971917 is 71917945109.

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.

It is a cyclic number.

It is not a de Polignac number, because 90154971917 - 2¹² = 90154967821 is a prime.

It is a super-2 number, since 2×90154971917² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90154961917) 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, 421284809 + ... + 421285022.

It is an arithmetic number, because the mean of its divisors is an integer number (22749385464).

Almost surely, 2^90154971917 is an apocalyptic number.

It is an amenable number.

90154971917 is a deficient number, since it is larger than the sum of its proper divisors (842569939).

90154971917 is a wasteful number, since it uses less digits than its factorization.

90154971917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 842569938.

The product of its (nonzero) digits is 714420, while the sum is 53.

The spelling of 90154971917 in words is "ninety billion, one hundred fifty-four million, nine hundred seventy-one thousand, nine hundred seventeen".