18516921193 has 4 divisors (see below), whose sum is σ = 18531090000. Its totient is φ = 18502752388.

The previous prime is 18516921131. The next prime is 18516921223. The reversal of 18516921193 is 39112961581.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18516921193 - 2¹⁷ = 18516790121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18516921113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7082443 + ... + 7085056.

It is an arithmetic number, because the mean of its divisors is an integer number (4632772500).

Almost surely, 2^18516921193 is an apocalyptic number.

It is an amenable number.

18516921193 is a deficient number, since it is larger than the sum of its proper divisors (14168807).

18516921193 is a wasteful number, since it uses less digits than its factorization.

18516921193 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14168806.

The product of its digits is 116640, while the sum is 46.

The spelling of 18516921193 in words is "eighteen billion, five hundred sixteen million, nine hundred twenty-one thousand, one hundred ninety-three".