18005240591 has 4 divisors (see below), whose sum is σ = 19390259112. Its totient is φ = 16620222072.

The previous prime is 18005240587. The next prime is 18005240597. The reversal of 18005240591 is 19504250081.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18005240591 - 2² = 18005240587 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 (18005240597) 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, 692509241 + ... + 692509266.

It is an arithmetic number, because the mean of its divisors is an integer number (4847564778).

Almost surely, 2^18005240591 is an apocalyptic number.

18005240591 is a deficient number, since it is larger than the sum of its proper divisors (1385018521).

18005240591 is a wasteful number, since it uses less digits than its factorization.

18005240591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1385018520.

The product of its (nonzero) digits is 14400, while the sum is 35.

The spelling of 18005240591 in words is "eighteen billion, five million, two hundred forty thousand, five hundred ninety-one".