16539643 has 2 divisors, whose sum is σ = 16539644. Its totient is φ = 16539642.

The previous prime is 16539641. The next prime is 16539673. The reversal of 16539643 is 34693561.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16539643 - 2¹ = 16539641 is a prime.

Together with 16539641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (16539641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8269821 + 8269822.

It is an arithmetic number, because the mean of its divisors is an integer number (8269822).

Almost surely, 2^16539643 is an apocalyptic number.

16539643 is a deficient number, since it is larger than the sum of its proper divisors (1).

16539643 is an equidigital number, since it uses as much as digits as its factorization.

16539643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 37.

The square root of 16539643 is about 4066.8959908018. The cubic root of 16539643 is about 254.7858923009.

The spelling of 16539643 in words is "sixteen million, five hundred thirty-nine thousand, six hundred forty-three".