16543437109 has 4 divisors (see below), whose sum is σ = 16547291404. Its totient is φ = 16539582816.

The previous prime is 16543437089. The next prime is 16543437139. The reversal of 16543437109 is 90173434561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10877864209 + 5665572900 = 104297^2 + 75270^2 .

It is a cyclic number.

It is not a de Polignac number, because 16543437109 - 2⁷ = 16543436981 is a prime.

It is a super-2 number, since 2×16543437109² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16543437139) 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, 1920702 + ... + 1929295.

It is an arithmetic number, because the mean of its divisors is an integer number (4136822851).

Almost surely, 2^16543437109 is an apocalyptic number.

It is an amenable number.

16543437109 is a deficient number, since it is larger than the sum of its proper divisors (3854295).

16543437109 is an equidigital number, since it uses as much as digits as its factorization.

16543437109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3854294.

The product of its (nonzero) digits is 272160, while the sum is 43.

The spelling of 16543437109 in words is "sixteen billion, five hundred forty-three million, four hundred thirty-seven thousand, one hundred nine".