18199719851 has 4 divisors (see below), whose sum is σ = 18247740600. Its totient is φ = 18151699104.

The previous prime is 18199719823. The next prime is 18199719883. The reversal of 18199719851 is 15891799181.

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 18199719851 - 2⁶ = 18199719787 is a prime.

It is a super-3 number, since 3×18199719851³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18199719821) 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, 24009806 + ... + 24010563.

It is an arithmetic number, because the mean of its divisors is an integer number (4561935150).

Almost surely, 2^18199719851 is an apocalyptic number.

18199719851 is a deficient number, since it is larger than the sum of its proper divisors (48020749).

18199719851 is an equidigital number, since it uses as much as digits as its factorization.

18199719851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48020748.

The product of its digits is 1632960, while the sum is 59.

The spelling of 18199719851 in words is "eighteen billion, one hundred ninety-nine million, seven hundred nineteen thousand, eight hundred fifty-one".