218959161 has 4 divisors (see below), whose sum is σ = 291945552. Its totient is φ = 145972772.

The previous prime is 218959159. The next prime is 218959163. The reversal of 218959161 is 161959812.

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 an interprime number because it is at equal distance from previous prime (218959159) and next prime (218959163).

It is a cyclic number.

It is not a de Polignac number, because 218959161 - 2¹ = 218959159 is a prime.

It is a super-2 number, since 2×218959161² = 95886228371647842, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (218959163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36493191 + ... + 36493196.

It is an arithmetic number, because the mean of its divisors is an integer number (72986388).

Almost surely, 2^218959161 is an apocalyptic number.

It is an amenable number.

218959161 is a deficient number, since it is larger than the sum of its proper divisors (72986391).

218959161 is an equidigital number, since it uses as much as digits as its factorization.

218959161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72986390.

The product of its digits is 38880, while the sum is 42.

The square root of 218959161 is about 14797.2687006758. The cubic root of 218959161 is about 602.7275459224.

The spelling of 218959161 in words is "two hundred eighteen million, nine hundred fifty-nine thousand, one hundred sixty-one".