812787218 has 4 divisors (see below), whose sum is σ = 1219180830. Its totient is φ = 406393608.

The previous prime is 812787203. The next prime is 812787319.

812787218 is nontrivially palindromic in base 10.

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., 649893049 + 162894169 = 25493^2 + 12763^2 .

It is an alternating number because its digits alternate between even and odd.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203196803 + ... + 203196806.

Almost surely, 2^812787218 is an apocalyptic number.

812787218 is a deficient number, since it is larger than the sum of its proper divisors (406393612).

812787218 is a wasteful number, since it uses less digits than its factorization.

812787218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 406393611.

The product of its digits is 100352, while the sum is 44.

The square root of 812787218 is about 28509.4233193167. The cubic root of 812787218 is about 933.2377295214.

The spelling of 812787218 in words is "eight hundred twelve million, seven hundred eighty-seven thousand, two hundred eighteen".