15990393691 has 2 divisors, whose sum is σ = 15990393692. Its totient is φ = 15990393690.

The previous prime is 15990393689. The next prime is 15990393737. The reversal of 15990393691 is 19639309951.

It is a weak prime.

It is an emirp because it is prime and its reverse (19639309951) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15990393691 - 2¹ = 15990393689 is a prime.

Together with 15990393689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (15990393191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7995196845 + 7995196846.

It is an arithmetic number, because the mean of its divisors is an integer number (7995196846).

Almost surely, 2^15990393691 is an apocalyptic number.

15990393691 is a deficient number, since it is larger than the sum of its proper divisors (1).

15990393691 is an equidigital number, since it uses as much as digits as its factorization.

15990393691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1771470, while the sum is 55.

The spelling of 15990393691 in words is "fifteen billion, nine hundred ninety million, three hundred ninety-three thousand, six hundred ninety-one".