19175744921 has 2 divisors, whose sum is σ = 19175744922. Its totient is φ = 19175744920.

The previous prime is 19175744899. The next prime is 19175744947. The reversal of 19175744921 is 12944757191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11490768025 + 7684976896 = 107195^2 + 87664^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19175744921 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19175744921.

It is not a weakly prime, because it can be changed into another prime (19175744981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9587872460 + 9587872461.

It is an arithmetic number, because the mean of its divisors is an integer number (9587872461).

Almost surely, 2^19175744921 is an apocalyptic number.

It is an amenable number.

19175744921 is a deficient number, since it is larger than the sum of its proper divisors (1).

19175744921 is an equidigital number, since it uses as much as digits as its factorization.

19175744921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 50.

The spelling of 19175744921 in words is "nineteen billion, one hundred seventy-five million, seven hundred forty-four thousand, nine hundred twenty-one".