16549943771 has 4 divisors (see below), whose sum is σ = 16566544512. Its totient is φ = 16533343032.

The previous prime is 16549943741. The next prime is 16549943777. The reversal of 16549943771 is 17734994561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17734994561 = 433 ⋅40958417.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16549943771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16549943777) 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, 8298875 + ... + 8300868.

It is an arithmetic number, because the mean of its divisors is an integer number (4141636128).

Almost surely, 2^16549943771 is an apocalyptic number.

16549943771 is a deficient number, since it is larger than the sum of its proper divisors (16600741).

16549943771 is an equidigital number, since it uses as much as digits as its factorization.

16549943771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16600740.

The product of its digits is 5715360, while the sum is 56.

The spelling of 16549943771 in words is "sixteen billion, five hundred forty-nine million, nine hundred forty-three thousand, seven hundred seventy-one".