1666836813 has 8 divisors (see below), whose sum is σ = 2252893888. Its totient is φ = 1096002144.

The previous prime is 1666836761. The next prime is 1666836817. The reversal of 1666836813 is 3186386661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-1666836813 is a prime.

It is a super-2 number, since 2×1666836813² = 5556689922343993938, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666836817) 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 7 ways as a sum of consecutive naturals, for example, 3805345 + ... + 3805782.

It is an arithmetic number, because the mean of its divisors is an integer number (281611736).

Almost surely, 2^1666836813 is an apocalyptic number.

It is an amenable number.

1666836813 is a deficient number, since it is larger than the sum of its proper divisors (586057075).

1666836813 is an equidigital number, since it uses as much as digits as its factorization.

1666836813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7611203.

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

The square root of 1666836813 is about 40826.9128516962. The cubic root of 1666836813 is about 1185.6714462807.

The spelling of 1666836813 in words is "one billion, six hundred sixty-six million, eight hundred thirty-six thousand, eight hundred thirteen".