16964721 has 10 divisors (see below), whose sum is σ = 25342482. Its totient is φ = 11309760.

The previous prime is 16964707. The next prime is 16964723. The reversal of 16964721 is 12746961.

16964721 is a `hidden beast` number, since 1 + 6 + 9 + 647 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13220496 + 3744225 = 3636^2 + 1935^2 .

It is not a de Polignac number, because 16964721 - 2⁹ = 16964209 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16964723) 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 in 9 ways as a sum of consecutive naturals, for example, 104640 + ... + 104801.

Almost surely, 2^16964721 is an apocalyptic number.

It is an amenable number.

16964721 is a deficient number, since it is larger than the sum of its proper divisors (8377761).

16964721 is an equidigital number, since it uses as much as digits as its factorization.

16964721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209453 (or 209444 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 16964721 is about 4118.8251965822. The cubic root of 16964721 is about 256.9501687414.

The spelling of 16964721 in words is "sixteen million, nine hundred sixty-four thousand, seven hundred twenty-one".