15982721 has 2 divisors, whose sum is σ = 15982722. Its totient is φ = 15982720.

The previous prime is 15982711. The next prime is 15982751. The reversal of 15982721 is 12728951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10857025 + 5125696 = 3295^2 + 2264^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15982721 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (15982711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7991360 + 7991361.

It is an arithmetic number, because the mean of its divisors is an integer number (7991361).

Almost surely, 2^15982721 is an apocalyptic number.

It is an amenable number.

15982721 is a deficient number, since it is larger than the sum of its proper divisors (1).

15982721 is an equidigital number, since it uses as much as digits as its factorization.

15982721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 35.

The square root of 15982721 is about 3997.8395415524. The cubic root of 15982721 is about 251.8934682401.

The spelling of 15982721 in words is "fifteen million, nine hundred eighty-two thousand, seven hundred twenty-one".