216742556861 has 16 divisors (see below), whose sum is σ = 222017953536. Its totient is φ = 211495823616.

The previous prime is 216742556857. The next prime is 216742556903. The reversal of 216742556861 is 168655247612.

It is a cyclic number.

It is not a de Polignac number, because 216742556861 - 2² = 216742556857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216742556461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22817465 + ... + 22826961.

It is an arithmetic number, because the mean of its divisors is an integer number (13876122096).

Almost surely, 2^216742556861 is an apocalyptic number.

It is an amenable number.

216742556861 is a deficient number, since it is larger than the sum of its proper divisors (5275396675).

216742556861 is an equidigital number, since it uses as much as digits as its factorization.

216742556861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10948.

The product of its digits is 4838400, while the sum is 53.

The spelling of 216742556861 in words is "two hundred sixteen billion, seven hundred forty-two million, five hundred fifty-six thousand, eight hundred sixty-one".