16543806373981 has 4 divisors (see below), whose sum is σ = 16551316047712. Its totient is φ = 16536296700252.

The previous prime is 16543806373979. The next prime is 16543806374041. The reversal of 16543806373981 is 18937360834561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16543806373981 - 2¹ = 16543806373979 is a prime.

It is a super-2 number, since 2×16543806373981² (a number of 27 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 (16543806373181) 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, 3754833561 + ... + 3754837966.

It is an arithmetic number, because the mean of its divisors is an integer number (4137829011928).

Almost surely, 2^{16543806373981} is an apocalyptic number.

It is an amenable number.

16543806373981 is a deficient number, since it is larger than the sum of its proper divisors (7509673731).

16543806373981 is an equidigital number, since it uses as much as digits as its factorization.

16543806373981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7509673730.

The product of its (nonzero) digits is 78382080, while the sum is 64.

The spelling of 16543806373981 in words is "sixteen trillion, five hundred forty-three billion, eight hundred six million, three hundred seventy-three thousand, nine hundred eighty-one".