16645971 has 16 divisors (see below), whose sum is σ = 23283360. Its totient is φ = 10563840.

The previous prime is 16645939. The next prime is 16645973. The reversal of 16645971 is 17954661.

It is not a de Polignac number, because 16645971 - 2⁵ = 16645939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16645973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5041 + ... + 7661.

It is an arithmetic number, because the mean of its divisors is an integer number (1455210).

Almost surely, 2^16645971 is an apocalyptic number.

16645971 is a deficient number, since it is larger than the sum of its proper divisors (6637389).

16645971 is a wasteful number, since it uses less digits than its factorization.

16645971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2726.

The product of its digits is 45360, while the sum is 39.

The square root of 16645971 is about 4079.9474261319. The cubic root of 16645971 is about 255.3307051080.

The spelling of 16645971 in words is "sixteen million, six hundred forty-five thousand, nine hundred seventy-one".