561818238 has 16 divisors (see below), whose sum is σ = 1134546816. Its totient is φ = 185454360.

The previous prime is 561818207. The next prime is 561818251. The reversal of 561818238 is 832818165.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 561818238.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 453928 + ... + 455163.

It is an arithmetic number, because the mean of its divisors is an integer number (70909176).

Almost surely, 2^561818238 is an apocalyptic number.

561818238 is an abundant number, since it is smaller than the sum of its proper divisors (572728578).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

561818238 is a wasteful number, since it uses less digits than its factorization.

561818238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909199.

The product of its digits is 92160, while the sum is 42.

The square root of 561818238 is about 23702.7052886374. The cubic root of 561818238 is about 825.1481768740.

The spelling of 561818238 in words is "five hundred sixty-one million, eight hundred eighteen thousand, two hundred thirty-eight".