15327721691 has 2 divisors, whose sum is σ = 15327721692. Its totient is φ = 15327721690.

The previous prime is 15327721657. The next prime is 15327721723. The reversal of 15327721691 is 19612772351.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15327721691 - 2¹⁸ = 15327459547 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (15327721621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7663860845 + 7663860846.

It is an arithmetic number, because the mean of its divisors is an integer number (7663860846).

Almost surely, 2^15327721691 is an apocalyptic number.

15327721691 is a deficient number, since it is larger than the sum of its proper divisors (1).

15327721691 is an equidigital number, since it uses as much as digits as its factorization.

15327721691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 44.

The spelling of 15327721691 in words is "fifteen billion, three hundred twenty-seven million, seven hundred twenty-one thousand, six hundred ninety-one".