19425943709 has 2 divisors, whose sum is σ = 19425943710. Its totient is φ = 19425943708.

The previous prime is 19425943651. The next prime is 19425943721. The reversal of 19425943709 is 90734952491.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19370515684 + 55428025 = 139178^2 + 7445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19425943709 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19425943739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9712971854 + 9712971855.

It is an arithmetic number, because the mean of its divisors is an integer number (9712971855).

Almost surely, 2^19425943709 is an apocalyptic number.

It is an amenable number.

19425943709 is a deficient number, since it is larger than the sum of its proper divisors (1).

19425943709 is an equidigital number, since it uses as much as digits as its factorization.

19425943709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2449440, while the sum is 53.

The spelling of 19425943709 in words is "nineteen billion, four hundred twenty-five million, nine hundred forty-three thousand, seven hundred nine".