15327721657 has 2 divisors, whose sum is σ = 15327721658. Its totient is φ = 15327721656.

The previous prime is 15327721621. The next prime is 15327721691. The reversal of 15327721657 is 75612772351.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13684554361 + 1643167296 = 116981^2 + 40536^2 .

It is a cyclic number.

It is not a de Polignac number, because 15327721657 - 2¹¹ = 15327719609 is a prime.

It is not a weakly prime, because it can be changed into another prime (15322721657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7663860828 + 7663860829.

It is an arithmetic number, because the mean of its divisors is an integer number (7663860829).

Almost surely, 2^15327721657 is an apocalyptic number.

It is an amenable number.

15327721657 is a deficient number, since it is larger than the sum of its proper divisors (1).

15327721657 is an equidigital number, since it uses as much as digits as its factorization.

15327721657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 617400, while the sum is 46.

The spelling of 15327721657 in words is "fifteen billion, three hundred twenty-seven million, seven hundred twenty-one thousand, six hundred fifty-seven".