1866336681 has 32 divisors (see below), whose sum is σ = 2751845760. Its totient is φ = 1115712000.

The previous prime is 1866336649. The next prime is 1866336691.

1866336681 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1866336681 - 2⁵ = 1866336649 is a prime.

It is a super-2 number, since 2×1866336681² = 6966425213692191522, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1866336681.

It is not an unprimeable number, because it can be changed into a prime (1866336691) 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 31 ways as a sum of consecutive naturals, for example, 1042335 + ... + 1044123.

It is an arithmetic number, because the mean of its divisors is an integer number (85995180).

Almost surely, 2^1866336681 is an apocalyptic number.

1866336681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1866336681 is a deficient number, since it is larger than the sum of its proper divisors (885509079).

1866336681 is a wasteful number, since it uses less digits than its factorization.

1866336681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2217.

The product of its digits is 746496, while the sum is 48.

The square root of 1866336681 is about 43201.1189785635. The cubic root of 1866336681 is about 1231.2039418091.

The spelling of 1866336681 in words is "one billion, eight hundred sixty-six million, three hundred thirty-six thousand, six hundred eighty-one".