16694721 has 8 divisors (see below), whose sum is σ = 24732960. Its totient is φ = 11129796.

The previous prime is 16694701. The next prime is 16694723. The reversal of 16694721 is 12749661.

It is not a de Polignac number, because 16694721 - 2¹¹ = 16692673 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16694723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 309135 + ... + 309188.

It is an arithmetic number, because the mean of its divisors is an integer number (3091620).

Almost surely, 2^16694721 is an apocalyptic number.

It is an amenable number.

16694721 is a deficient number, since it is larger than the sum of its proper divisors (8038239).

16694721 is an equidigital number, since it uses as much as digits as its factorization.

16694721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618332 (or 618326 counting only the distinct ones).

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

The square root of 16694721 is about 4085.9174000462. The cubic root of 16694721 is about 255.5797191253.

The spelling of 16694721 in words is "sixteen million, six hundred ninety-four thousand, seven hundred twenty-one".