16640639 has 8 divisors (see below), whose sum is σ = 17309760. Its totient is φ = 15983136.

The previous prime is 16640621. The next prime is 16640647. The reversal of 16640639 is 93604661.

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

It is a cyclic number.

It is not a de Polignac number, because 16640639 - 2²⁰ = 15592063 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16640599 and 16640608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16640839) 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 7 ways as a sum of consecutive naturals, for example, 77 + ... + 5769.

It is an arithmetic number, because the mean of its divisors is an integer number (2163720).

Almost surely, 2^16640639 is an apocalyptic number.

16640639 is a deficient number, since it is larger than the sum of its proper divisors (669121).

16640639 is an equidigital number, since it uses as much as digits as its factorization.

16640639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5809.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 16640639 is about 4079.2939340038. The cubic root of 16640639 is about 255.3034398775.

The spelling of 16640639 in words is "sixteen million, six hundred forty thousand, six hundred thirty-nine".