19389990691 has 2 divisors, whose sum is σ = 19389990692. Its totient is φ = 19389990690.

The previous prime is 19389990673. The next prime is 19389990757. The reversal of 19389990691 is 19609998391.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19389990691 - 2¹³ = 19389982499 is a prime.

It is not a weakly prime, because it can be changed into another prime (19389993691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9694995345 + 9694995346.

It is an arithmetic number, because the mean of its divisors is an integer number (9694995346).

Almost surely, 2^19389990691 is an apocalyptic number.

19389990691 is a deficient number, since it is larger than the sum of its proper divisors (1).

19389990691 is an equidigital number, since it uses as much as digits as its factorization.

19389990691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8503056, while the sum is 64.

The spelling of 19389990691 in words is "nineteen billion, three hundred eighty-nine million, nine hundred ninety thousand, six hundred ninety-one".