19638763691 has 2 divisors, whose sum is σ = 19638763692. Its totient is φ = 19638763690.

The previous prime is 19638763589. The next prime is 19638763733. The reversal of 19638763691 is 19636783691.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19638763691 - 2¹⁰ = 19638762667 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19638763691.

It is not a weakly prime, because it can be changed into another prime (19638763891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9819381845 + 9819381846.

It is an arithmetic number, because the mean of its divisors is an integer number (9819381846).

Almost surely, 2^19638763691 is an apocalyptic number.

19638763691 is a deficient number, since it is larger than the sum of its proper divisors (1).

19638763691 is an equidigital number, since it uses as much as digits as its factorization.

19638763691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8817984, while the sum is 59.

The spelling of 19638763691 in words is "nineteen billion, six hundred thirty-eight million, seven hundred sixty-three thousand, six hundred ninety-one".