18921327851 has 4 divisors (see below), whose sum is σ = 18921865032. Its totient is φ = 18920790672.

The previous prime is 18921327847. The next prime is 18921327853. The reversal of 18921327851 is 15872312981.

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 18921327851 - 2² = 18921327847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18921327796 and 18921327805.

It is not an unprimeable number, because it can be changed into a prime (18921327853) 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, 211745 + ... + 287538.

It is an arithmetic number, because the mean of its divisors is an integer number (4730466258).

Almost surely, 2^18921327851 is an apocalyptic number.

18921327851 is a deficient number, since it is larger than the sum of its proper divisors (537181).

18921327851 is an equidigital number, since it uses as much as digits as its factorization.

18921327851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537180.

The product of its digits is 241920, while the sum is 47.

The spelling of 18921327851 in words is "eighteen billion, nine hundred twenty-one million, three hundred twenty-seven thousand, eight hundred fifty-one".