19397634391 has 2 divisors, whose sum is σ = 19397634392. Its totient is φ = 19397634390.

The previous prime is 19397634379. The next prime is 19397634419. The reversal of 19397634391 is 19343679391.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19397634391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19397634301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9698817195 + 9698817196.

It is an arithmetic number, because the mean of its divisors is an integer number (9698817196).

Almost surely, 2^19397634391 is an apocalyptic number.

19397634391 is a deficient number, since it is larger than the sum of its proper divisors (1).

19397634391 is an equidigital number, since it uses as much as digits as its factorization.

19397634391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3306744, while the sum is 55.

The spelling of 19397634391 in words is "nineteen billion, three hundred ninety-seven million, six hundred thirty-four thousand, three hundred ninety-one".