90919818894191 has 16 divisors (see below), whose sum is σ = 105612619169280. Its totient is φ = 76653102595680.

The previous prime is 90919818894181. The next prime is 90919818894199. The reversal of 90919818894191 is 19149881891909.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90919818894191 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 (90919818894199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57716270 + ... + 59270628.

It is an arithmetic number, because the mean of its divisors is an integer number (6600788698080).

Almost surely, 2^{90919818894191} is an apocalyptic number.

90919818894191 is a deficient number, since it is larger than the sum of its proper divisors (14692800275089).

90919818894191 is a wasteful number, since it uses less digits than its factorization.

90919818894191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1691414.

The product of its (nonzero) digits is 120932352, while the sum is 77.

The spelling of 90919818894191 in words is "ninety trillion, nine hundred nineteen billion, eight hundred eighteen million, eight hundred ninety-four thousand, one hundred ninety-one".