18591322499 has 8 divisors (see below), whose sum is σ = 18914749440. Its totient is φ = 18268173000.

The previous prime is 18591322481. The next prime is 18591322501. The reversal of 18591322499 is 99422319581.

It is a happy number.

It is a Cunningham number, because it is equal to 136350²-1.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18591322499 - 2²⁸ = 18322887043 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18591322499.

It is not an unprimeable number, because it can be changed into a prime (18591322699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68174 + ... + 204524.

It is an arithmetic number, because the mean of its divisors is an integer number (2364343680).

Almost surely, 2^18591322499 is an apocalyptic number.

18591322499 is a deficient number, since it is larger than the sum of its proper divisors (323426941).

18591322499 is a wasteful number, since it uses less digits than its factorization.

18591322499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138721.

The product of its digits is 1399680, while the sum is 53.

The spelling of 18591322499 in words is "eighteen billion, five hundred ninety-one million, three hundred twenty-two thousand, four hundred ninety-nine".