16644491 has 8 divisors (see below), whose sum is σ = 17128800. Its totient is φ = 16166592.

The previous prime is 16644469. The next prime is 16644527. The reversal of 16644491 is 19444661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16644491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16644391) 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 in 7 ways as a sum of consecutive naturals, for example, 3935 + ... + 6983.

It is an arithmetic number, because the mean of its divisors is an integer number (2141100).

Almost surely, 2^16644491 is an apocalyptic number.

16644491 is a deficient number, since it is larger than the sum of its proper divisors (484309).

16644491 is a wasteful number, since it uses less digits than its factorization.

16644491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3205.

The product of its digits is 20736, while the sum is 35.

The square root of 16644491 is about 4079.7660472140. The cubic root of 16644491 is about 255.3231376984.

The spelling of 16644491 in words is "sixteen million, six hundred forty-four thousand, four hundred ninety-one".