19391534321 has 2 divisors, whose sum is σ = 19391534322. Its totient is φ = 19391534320.

The previous prime is 19391534297. The next prime is 19391534333. The reversal of 19391534321 is 12343519391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15027082225 + 4364452096 = 122585^2 + 66064^2 .

It is a cyclic number.

It is not a de Polignac number, because 19391534321 - 2⁶ = 19391534257 is a prime.

It is not a weakly prime, because it can be changed into another prime (19391584321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9695767160 + 9695767161.

It is an arithmetic number, because the mean of its divisors is an integer number (9695767161).

Almost surely, 2^19391534321 is an apocalyptic number.

It is an amenable number.

19391534321 is a deficient number, since it is larger than the sum of its proper divisors (1).

19391534321 is an equidigital number, since it uses as much as digits as its factorization.

19391534321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87480, while the sum is 41.

The spelling of 19391534321 in words is "nineteen billion, three hundred ninety-one million, five hundred thirty-four thousand, three hundred twenty-one".