16339681 has 4 divisors (see below), whose sum is σ = 16781332. Its totient is φ = 15898032.

The previous prime is 16339667. The next prime is 16339709. The reversal of 16339681 is 18693361.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18693361 = 191 ⋅97871.

It can be written as a sum of positive squares in 2 ways, for example, as 14861025 + 1478656 = 3855^2 + 1216^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16339681 is a prime.

It is a super-2 number, since 2×16339681² = 533970350363522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 441613 = 16339681 / (1 + 6 + 3 + 3 + 9 + 6 + 8 + 1).

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 16339681.

It is not an unprimeable number, because it can be changed into a prime (16339181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220770 + ... + 220843.

It is an arithmetic number, because the mean of its divisors is an integer number (4195333).

Almost surely, 2^16339681 is an apocalyptic number.

It is an amenable number.

16339681 is a deficient number, since it is larger than the sum of its proper divisors (441651).

16339681 is an equidigital number, since it uses as much as digits as its factorization.

16339681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441650.

The product of its digits is 23328, while the sum is 37.

The square root of 16339681 is about 4042.2371281260. The cubic root of 16339681 is about 253.7549510063.

It can be divided in two parts, 16339 and 681, that added together give a triangular number (17020 = T₁₈₄).

The spelling of 16339681 in words is "sixteen million, three hundred thirty-nine thousand, six hundred eighty-one".