16431 has 4 divisors (see below), whose sum is σ = 21912. Its totient is φ = 10952.

The previous prime is 16427. The next prime is 16433. The reversal of 16431 is 13461.

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 16431 - 2² = 16427 is a prime.

It is a super-2 number, since 2×16431² = 539955522, which contains 22 as substring.

It is a d-powerful number, because it can be written as 1 + 6² + 4⁷ + 3² + 1 .

It is a D-number.

16431 is a lucky number.

It is a plaindrome in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 16431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16433) 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, 2736 + ... + 2741.

It is an arithmetic number, because the mean of its divisors is an integer number (5478).

2¹⁶⁴³¹ is an apocalyptic number.

16431 is a deficient number, since it is larger than the sum of its proper divisors (5481).

16431 is an equidigital number, since it uses as much as digits as its factorization.

16431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5480.

The product of its digits is 72, while the sum is 15.

The square root of 16431 is about 128.1834622719. The cubic root of 16431 is about 25.4226800547.

Adding to 16431 its reverse (13461), we get a palindrome (29892).

The spelling of 16431 in words is "sixteen thousand, four hundred thirty-one".