561117218 has 4 divisors (see below), whose sum is σ = 841675830. Its totient is φ = 280558608.

The previous prime is 561117217. The next prime is 561117229. The reversal of 561117218 is 812711165.

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

It can be written as a sum of positive squares in only one way, i.e., 489427129 + 71690089 = 22123^2 + 8467^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (561117211) 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 as a sum of consecutive naturals, namely, 140279303 + ... + 140279306.

Almost surely, 2^561117218 is an apocalyptic number.

561117218 is a deficient number, since it is larger than the sum of its proper divisors (280558612).

561117218 is a wasteful number, since it uses less digits than its factorization.

561117218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280558611.

The product of its digits is 3360, while the sum is 32.

The square root of 561117218 is about 23687.9129093299. The cubic root of 561117218 is about 824.8048356226.

The spelling of 561117218 in words is "five hundred sixty-one million, one hundred seventeen thousand, two hundred eighteen".