1866664801 has 2 divisors, whose sum is σ = 1866664802. Its totient is φ = 1866664800.

The previous prime is 1866664781. The next prime is 1866664819. The reversal of 1866664801 is 1084666681.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1812715776 + 53949025 = 42576^2 + 7345^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866664801 - 2⁷ = 1866664673 is a prime.

It is not a weakly prime, because it can be changed into another prime (1866664871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 933332400 + 933332401.

It is an arithmetic number, because the mean of its divisors is an integer number (933332401).

Almost surely, 2^1866664801 is an apocalyptic number.

It is an amenable number.

1866664801 is a deficient number, since it is larger than the sum of its proper divisors (1).

1866664801 is an equidigital number, since it uses as much as digits as its factorization.

1866664801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 331776, while the sum is 46.

The square root of 1866664801 is about 43204.9163984841. The cubic root of 1866664801 is about 1231.2760900928.

The spelling of 1866664801 in words is "one billion, eight hundred sixty-six million, six hundred sixty-four thousand, eight hundred one".