16840643 has 4 divisors (see below), whose sum is σ = 16878600. Its totient is φ = 16802688.

The previous prime is 16840633. The next prime is 16840721. The reversal of 16840643 is 34604861.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16840643 - 2¹⁰ = 16839619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16840613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18305 + ... + 19202.

It is an arithmetic number, because the mean of its divisors is an integer number (4219650).

Almost surely, 2^16840643 is an apocalyptic number.

16840643 is a deficient number, since it is larger than the sum of its proper divisors (37957).

16840643 is an equidigital number, since it uses as much as digits as its factorization.

16840643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37956.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 16840643 is about 4103.7352497450. The cubic root of 16840643 is about 256.3222007138.

The spelling of 16840643 in words is "sixteen million, eight hundred forty thousand, six hundred forty-three".