15643 has 2 divisors, whose sum is σ = 15644. Its totient is φ = 15642.

The previous prime is 15641. The next prime is 15647. The reversal of 15643 is 34651.

It is a weak prime.

It is an emirp because it is prime and its reverse (34651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15643 - 2¹ = 15641 is a prime.

Together with 15641, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 15643.

It is not a weakly prime, because it can be changed into another prime (15641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7821 + 7822.

It is an arithmetic number, because the mean of its divisors is an integer number (7822).

2¹⁵⁶⁴³ is an apocalyptic number.

15643 is a deficient number, since it is larger than the sum of its proper divisors (1).

15643 is an equidigital number, since it uses as much as digits as its factorization.

It is an anagram of its base 7 representation: 15643 = (63415)₇.

15643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 19.

The square root of 15643 is about 125.0719792759. The cubic root of 15643 is about 25.0095963160.

The spelling of 15643 in words is "fifteen thousand, six hundred forty-three".