2791813666 has 4 divisors (see below), whose sum is σ = 4187720502. Its totient is φ = 1395906832.

The previous prime is 2791813663. The next prime is 2791813667. The reversal of 2791813666 is 6663181972.

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., 2790058041 + 1755625 = 52821^2 + 1325^2 .

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (2791813663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 697953415 + ... + 697953418.

Almost surely, 2^2791813666 is an apocalyptic number.

2791813666 is a deficient number, since it is larger than the sum of its proper divisors (1395906836).

2791813666 is a wasteful number, since it uses less digits than its factorization.

2791813666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395906835.

The product of its digits is 653184, while the sum is 49.

The square root of 2791813666 is about 52837.6160135940. The cubic root of 2791813666 is about 1408.0847974417.

The spelling of 2791813666 in words is "two billion, seven hundred ninety-one million, eight hundred thirteen thousand, six hundred sixty-six".