818555966 has 4 divisors (see below), whose sum is σ = 1227833952. Its totient is φ = 409277982.

The previous prime is 818555963. The next prime is 818555981. The reversal of 818555966 is 669555818.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 669555818 = 2 ⋅334777909.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (818555963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 204638990 + ... + 204638993.

It is an arithmetic number, because the mean of its divisors is an integer number (306958488).

Almost surely, 2^818555966 is an apocalyptic number.

818555966 is a deficient number, since it is larger than the sum of its proper divisors (409277986).

818555966 is a wasteful number, since it uses less digits than its factorization.

818555966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409277985.

The product of its digits is 2592000, while the sum is 53.

The square root of 818555966 is about 28610.4170888856. The cubic root of 818555966 is about 935.4404079267.

The spelling of 818555966 in words is "eight hundred eighteen million, five hundred fifty-five thousand, nine hundred sixty-six".