216809998727 has 4 divisors (see below), whose sum is σ = 247782855696. Its totient is φ = 185837141760.

The previous prime is 216809998703. The next prime is 216809998747. The reversal of 216809998727 is 727899908612.

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

It is a cyclic number.

It is not a de Polignac number, because 216809998727 - 2²⁴ = 216793221511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216809998747) 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, 15486428474 + ... + 15486428487.

It is an arithmetic number, because the mean of its divisors is an integer number (61945713924).

Almost surely, 2^216809998727 is an apocalyptic number.

216809998727 is a deficient number, since it is larger than the sum of its proper divisors (30972856969).

216809998727 is an equidigital number, since it uses as much as digits as its factorization.

216809998727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30972856968.

The product of its (nonzero) digits is 54867456, while the sum is 68.

The spelling of 216809998727 in words is "two hundred sixteen billion, eight hundred nine million, nine hundred ninety-eight thousand, seven hundred twenty-seven".