18791449511 has 4 divisors (see below), whose sum is σ = 19896828912. Its totient is φ = 17686070112.

The previous prime is 18791449507. The next prime is 18791449529. The reversal of 18791449511 is 11594419781.

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 18791449511 - 2² = 18791449507 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 18791449511.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18791449531) 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, 552689675 + ... + 552689708.

It is an arithmetic number, because the mean of its divisors is an integer number (4974207228).

Almost surely, 2^18791449511 is an apocalyptic number.

18791449511 is a deficient number, since it is larger than the sum of its proper divisors (1105379401).

18791449511 is a wasteful number, since it uses less digits than its factorization.

18791449511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105379400.

The product of its digits is 362880, while the sum is 50.

The spelling of 18791449511 in words is "eighteen billion, seven hundred ninety-one million, four hundred forty-nine thousand, five hundred eleven".