19817974699 has 2 divisors, whose sum is σ = 19817974700. Its totient is φ = 19817974698.

The previous prime is 19817974661. The next prime is 19817974763. The reversal of 19817974699 is 99647971891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19817974699 - 2⁷ = 19817974571 is a prime.

It is not a weakly prime, because it can be changed into another prime (19817978699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9908987349 + 9908987350.

It is an arithmetic number, because the mean of its divisors is an integer number (9908987350).

Almost surely, 2^19817974699 is an apocalyptic number.

19817974699 is a deficient number, since it is larger than the sum of its proper divisors (1).

19817974699 is an equidigital number, since it uses as much as digits as its factorization.

19817974699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61725888, while the sum is 70.

The spelling of 19817974699 in words is "nineteen billion, eight hundred seventeen million, nine hundred seventy-four thousand, six hundred ninety-nine".