16375721 has 2 divisors, whose sum is σ = 16375722. Its totient is φ = 16375720.

The previous prime is 16375703. The next prime is 16375727. The reversal of 16375721 is 12757361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13957696 + 2418025 = 3736^2 + 1555^2 .

It is a cyclic number.

It is not a de Polignac number, because 16375721 - 2¹⁰ = 16374697 is a prime.

It is not a weakly prime, because it can be changed into another prime (16375727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8187860 + 8187861.

It is an arithmetic number, because the mean of its divisors is an integer number (8187861).

Almost surely, 2^16375721 is an apocalyptic number.

It is an amenable number.

16375721 is a deficient number, since it is larger than the sum of its proper divisors (1).

16375721 is an equidigital number, since it uses as much as digits as its factorization.

16375721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8820, while the sum is 32.

The square root of 16375721 is about 4046.6926001366. The cubic root of 16375721 is about 253.9413808555.

The spelling of 16375721 in words is "sixteen million, three hundred seventy-five thousand, seven hundred twenty-one".