1820678866 has 4 divisors (see below), whose sum is σ = 2731018302. Its totient is φ = 910339432.

The previous prime is 1820678861. The next prime is 1820678941. The reversal of 1820678866 is 6688760281.

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., 1163833225 + 656845641 = 34115^2 + 25629^2 .

It is not an unprimeable number, because it can be changed into a prime (1820678861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 455169715 + ... + 455169718.

Almost surely, 2^1820678866 is an apocalyptic number.

1820678866 is a deficient number, since it is larger than the sum of its proper divisors (910339436).

1820678866 is an equidigital number, since it uses as much as digits as its factorization.

1820678866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910339435.

The product of its (nonzero) digits is 1548288, while the sum is 52.

The square root of 1820678866 is about 42669.4137058385. The cubic root of 1820678866 is about 1221.0809344089.

The spelling of 1820678866 in words is "one billion, eight hundred twenty million, six hundred seventy-eight thousand, eight hundred sixty-six".