9904891591 has 16 divisors (see below), whose sum is σ = 11542886208. Its totient is φ = 8322912000.

The previous prime is 9904891583. The next prime is 9904891637. The reversal of 9904891591 is 1951984099.

It is a cyclic number.

It is not a de Polignac number, because 9904891591 - 2³ = 9904891583 is a prime.

It is a super-2 number, since 2×9904891591² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9904897591) 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, 472411 + ... + 492931.

It is an arithmetic number, because the mean of its divisors is an integer number (721430388).

Almost surely, 2^9904891591 is an apocalyptic number.

9904891591 is a deficient number, since it is larger than the sum of its proper divisors (1637994617).

9904891591 is a wasteful number, since it uses less digits than its factorization.

9904891591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21882.

The product of its (nonzero) digits is 1049760, while the sum is 55.

The square root of 9904891591 is about 99523.3218446812. The cubic root of 9904891591 is about 2147.5827595054.

The spelling of 9904891591 in words is "nine billion, nine hundred four million, eight hundred ninety-one thousand, five hundred ninety-one".