1236220866 has 40 divisors (see below), whose sum is σ = 2822335164. Its totient is φ = 404295840.

The previous prime is 1236220861. The next prime is 1236220873. The reversal of 1236220866 is 6680226321.

1236220866 is a `hidden beast` number, since 1 + 23 + 622 + 0 + 8 + 6 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1209996225 + 26224641 = 34785^2 + 5121^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1236220866.

It is not an unprimeable number, because it can be changed into a prime (1236220861) by changing a digit.

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 19 ways as a sum of consecutive naturals, for example, 63405 + ... + 80576.

Almost surely, 2^1236220866 is an apocalyptic number.

1236220866 is an abundant number, since it is smaller than the sum of its proper divisors (1586114298).

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

1236220866 is a wasteful number, since it uses less digits than its factorization.

1236220866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144048 (or 144039 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 1236220866 is about 35159.9326791164. The cubic root of 1236220866 is about 1073.2445453562.

The spelling of 1236220866 in words is "one billion, two hundred thirty-six million, two hundred twenty thousand, eight hundred sixty-six".