16643431 has 16 divisors (see below), whose sum is σ = 19600704. Its totient is φ = 13837824.

The previous prime is 16643401. The next prime is 16643447. The reversal of 16643431 is 13434661.

It is not a de Polignac number, because 16643431 - 2⁵ = 16643399 is a prime.

It is a super-2 number, since 2×16643431² = 554007590903522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 16643431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16643401) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41725 + ... + 42121.

It is an arithmetic number, because the mean of its divisors is an integer number (1225044).

Almost surely, 2^16643431 is an apocalyptic number.

16643431 is a deficient number, since it is larger than the sum of its proper divisors (2957273).

16643431 is a wasteful number, since it uses less digits than its factorization.

16643431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570.

The product of its digits is 5184, while the sum is 28.

The square root of 16643431 is about 4079.6361357356. The cubic root of 16643431 is about 255.3177175212.

The spelling of 16643431 in words is "sixteen million, six hundred forty-three thousand, four hundred thirty-one".