16969721 has 2 divisors, whose sum is σ = 16969722. Its totient is φ = 16969720.

The previous prime is 16969697. The next prime is 16969747. The reversal of 16969721 is 12796961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13690000 + 3279721 = 3700^2 + 1811^2 .

It is a cyclic number.

It is not a de Polignac number, because 16969721 - 2¹⁰ = 16968697 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 (16960721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8484860 + 8484861.

It is an arithmetic number, because the mean of its divisors is an integer number (8484861).

Almost surely, 2^16969721 is an apocalyptic number.

It is an amenable number.

16969721 is a deficient number, since it is larger than the sum of its proper divisors (1).

16969721 is an equidigital number, since it uses as much as digits as its factorization.

16969721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 41.

The square root of 16969721 is about 4119.4321210575. The cubic root of 16969721 is about 256.9754098412.

The spelling of 16969721 in words is "sixteen million, nine hundred sixty-nine thousand, seven hundred twenty-one".