1866685321 has 2 divisors, whose sum is σ = 1866685322. Its totient is φ = 1866685320.

The previous prime is 1866685309. The next prime is 1866685393. The reversal of 1866685321 is 1235866681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1469878921 + 396806400 = 38339^2 + 19920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866685321 - 2⁷ = 1866685193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1866685421) 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 as a sum of consecutive naturals, namely, 933342660 + 933342661.

It is an arithmetic number, because the mean of its divisors is an integer number (933342661).

Almost surely, 2^1866685321 is an apocalyptic number.

It is an amenable number.

1866685321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1866685321 is an equidigital number, since it uses as much as digits as its factorization.

1866685321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 414720, while the sum is 46.

The square root of 1866685321 is about 43205.1538708057. The cubic root of 1866685321 is about 1231.2806018282.

The spelling of 1866685321 in words is "one billion, eight hundred sixty-six million, six hundred eighty-five thousand, three hundred twenty-one".