19972190321 has 2 divisors, whose sum is σ = 19972190322. Its totient is φ = 19972190320.

The previous prime is 19972190267. The next prime is 19972190339. The reversal of 19972190321 is 12309127991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12838023025 + 7134167296 = 113305^2 + 84464^2 .

It is a cyclic number.

It is not a de Polignac number, because 19972190321 - 2²⁶ = 19905081457 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19972190341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9986095160 + 9986095161.

It is an arithmetic number, because the mean of its divisors is an integer number (9986095161).

Almost surely, 2^19972190321 is an apocalyptic number.

It is an amenable number.

19972190321 is a deficient number, since it is larger than the sum of its proper divisors (1).

19972190321 is an equidigital number, since it uses as much as digits as its factorization.

19972190321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 61236, while the sum is 44.

The spelling of 19972190321 in words is "nineteen billion, nine hundred seventy-two million, one hundred ninety thousand, three hundred twenty-one".