19471993999 has 2 divisors, whose sum is σ = 19471994000. Its totient is φ = 19471993998.

The previous prime is 19471993993. The next prime is 19471994041. The reversal of 19471993999 is 99939917491.

It is a weak prime.

It is an emirp because it is prime and its reverse (99939917491) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19471993999 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19471993993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9735996999 + 9735997000.

It is an arithmetic number, because the mean of its divisors is an integer number (9735997000).

Almost surely, 2^19471993999 is an apocalyptic number.

19471993999 is a deficient number, since it is larger than the sum of its proper divisors (1).

19471993999 is an equidigital number, since it uses as much as digits as its factorization.

19471993999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 44641044, while the sum is 70.

The spelling of 19471993999 in words is "nineteen billion, four hundred seventy-one million, nine hundred ninety-three thousand, nine hundred ninety-nine".