18733874921 has 4 divisors (see below), whose sum is σ = 18766799700. Its totient is φ = 18700950144.

The previous prime is 18733874881. The next prime is 18733874933. The reversal of 18733874921 is 12947833781.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5775240025 + 12958634896 = 75995^2 + 113836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18733874921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18733874941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16461536 + ... + 16462673.

It is an arithmetic number, because the mean of its divisors is an integer number (4691699925).

Almost surely, 2^18733874921 is an apocalyptic number.

It is an amenable number.

18733874921 is a deficient number, since it is larger than the sum of its proper divisors (32924779).

18733874921 is an equidigital number, since it uses as much as digits as its factorization.

18733874921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32924778.

The product of its digits is 2032128, while the sum is 53.

The spelling of 18733874921 in words is "eighteen billion, seven hundred thirty-three million, eight hundred seventy-four thousand, nine hundred twenty-one".