15970186721 has 2 divisors, whose sum is σ = 15970186722. Its totient is φ = 15970186720.

The previous prime is 15970186711. The next prime is 15970186723. The reversal of 15970186721 is 12768107951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8397706321 + 7572480400 = 91639^2 + 87020^2 .

It is a cyclic number.

It is not a de Polignac number, because 15970186721 - 2⁶ = 15970186657 is a prime.

Together with 15970186723, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (15970186723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7985093360 + 7985093361.

It is an arithmetic number, because the mean of its divisors is an integer number (7985093361).

Almost surely, 2^15970186721 is an apocalyptic number.

It is an amenable number.

15970186721 is a deficient number, since it is larger than the sum of its proper divisors (1).

15970186721 is an equidigital number, since it uses as much as digits as its factorization.

15970186721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 211680, while the sum is 47.

The spelling of 15970186721 in words is "fifteen billion, nine hundred seventy million, one hundred eighty-six thousand, seven hundred twenty-one".