19609240921 has 2 divisors, whose sum is σ = 19609240922. Its totient is φ = 19609240920.

The previous prime is 19609240913. The next prime is 19609240927. The reversal of 19609240921 is 12904290691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10268984896 + 9340256025 = 101336^2 + 96645^2 .

It is a cyclic number.

It is not a de Polignac number, because 19609240921 - 2³ = 19609240913 is a prime.

It is not a weakly prime, because it can be changed into another prime (19609240927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9804620460 + 9804620461.

It is an arithmetic number, because the mean of its divisors is an integer number (9804620461).

Almost surely, 2^19609240921 is an apocalyptic number.

It is an amenable number.

19609240921 is a deficient number, since it is larger than the sum of its proper divisors (1).

19609240921 is an equidigital number, since it uses as much as digits as its factorization.

19609240921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 43.

The spelling of 19609240921 in words is "nineteen billion, six hundred nine million, two hundred forty thousand, nine hundred twenty-one".