19818086399 has 2 divisors, whose sum is σ = 19818086400. Its totient is φ = 19818086398.

The previous prime is 19818086389. The next prime is 19818086419. The reversal of 19818086399 is 99368081891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19818086399 - 2⁴ = 19818086383 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19818086339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9909043199 + 9909043200.

It is an arithmetic number, because the mean of its divisors is an integer number (9909043200).

Almost surely, 2^19818086399 is an apocalyptic number.

19818086399 is a deficient number, since it is larger than the sum of its proper divisors (1).

19818086399 is an equidigital number, since it uses as much as digits as its factorization.

19818086399 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6718464, while the sum is 62.

The spelling of 19818086399 in words is "nineteen billion, eight hundred eighteen million, eighty-six thousand, three hundred ninety-nine".