18947291851 has 2 divisors, whose sum is σ = 18947291852. Its totient is φ = 18947291850.

The previous prime is 18947291833. The next prime is 18947291899. The reversal of 18947291851 is 15819274981.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18947291851 - 2¹⁵ = 18947259083 is a prime.

It is a super-3 number, since 3×18947291851³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 18947291792 and 18947291801.

It is not a weakly prime, because it can be changed into another prime (18947291821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9473645925 + 9473645926.

It is an arithmetic number, because the mean of its divisors is an integer number (9473645926).

Almost surely, 2^18947291851 is an apocalyptic number.

18947291851 is a deficient number, since it is larger than the sum of its proper divisors (1).

18947291851 is an equidigital number, since it uses as much as digits as its factorization.

18947291851 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1451520, while the sum is 55.

The spelling of 18947291851 in words is "eighteen billion, nine hundred forty-seven million, two hundred ninety-one thousand, eight hundred fifty-one".