18999981047 has 2 divisors, whose sum is σ = 18999981048. Its totient is φ = 18999981046.

The previous prime is 18999981017. The next prime is 18999981053. The reversal of 18999981047 is 74018999981.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18999981047 - 2¹⁰ = 18999980023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18999981017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9499990523 + 9499990524.

It is an arithmetic number, because the mean of its divisors is an integer number (9499990524).

Almost surely, 2^18999981047 is an apocalyptic number.

18999981047 is a deficient number, since it is larger than the sum of its proper divisors (1).

18999981047 is an equidigital number, since it uses as much as digits as its factorization.

18999981047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11757312, while the sum is 65.

The spelling of 18999981047 in words is "eighteen billion, nine hundred ninety-nine million, nine hundred eighty-one thousand, forty-seven".