218164556261 has 8 divisors (see below), whose sum is σ = 227732486400. Its totient is φ = 208754773920.

The previous prime is 218164556221. The next prime is 218164556263. The reversal of 218164556261 is 162655461812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 218164556261 - 2²⁶ = 218097447397 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 (218164556263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39534131 + ... + 39539648.

It is an arithmetic number, because the mean of its divisors is an integer number (28466560800).

Almost surely, 2^218164556261 is an apocalyptic number.

It is an amenable number.

218164556261 is a deficient number, since it is larger than the sum of its proper divisors (9567930139).

218164556261 is an equidigital number, since it uses as much as digits as its factorization.

218164556261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79073899.

The product of its digits is 691200, while the sum is 47.

The spelling of 218164556261 in words is "two hundred eighteen billion, one hundred sixty-four million, five hundred fifty-six thousand, two hundred sixty-one".