16643443 has 4 divisors (see below), whose sum is σ = 16763320. Its totient is φ = 16523568.

The previous prime is 16643401. The next prime is 16643447. The reversal of 16643443 is 34434661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34434661 = 1361 ⋅25301.

It is a cyclic number.

It is not a de Polignac number, because 16643443 - 2⁹ = 16642931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16643447) 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, 59730 + ... + 60007.

It is an arithmetic number, because the mean of its divisors is an integer number (4190830).

Almost surely, 2^16643443 is an apocalyptic number.

16643443 is a deficient number, since it is larger than the sum of its proper divisors (119877).

16643443 is a wasteful number, since it uses less digits than its factorization.

16643443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119876.

The product of its digits is 20736, while the sum is 31.

The square root of 16643443 is about 4079.6376064548. The cubic root of 16643443 is about 255.3177788830.

The spelling of 16643443 in words is "sixteen million, six hundred forty-three thousand, four hundred forty-three".