2666691878 has 16 divisors (see below), whose sum is σ = 4039787520. Its totient is φ = 1320110856.

The previous prime is 2666691871. The next prime is 2666691883. The reversal of 2666691878 is 8781966662.

It is a super-2 number, since 2×2666691878² = 14222491144382333768, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2666691871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 579575 + ... + 584157.

It is an arithmetic number, because the mean of its divisors is an integer number (252486720).

Almost surely, 2^2666691878 is an apocalyptic number.

2666691878 is a deficient number, since it is larger than the sum of its proper divisors (1373095642).

2666691878 is a wasteful number, since it uses less digits than its factorization.

2666691878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7411.

The product of its digits is 10450944, while the sum is 59.

The square root of 2666691878 is about 51640.0220565406. The cubic root of 2666691878 is about 1386.7269188280.

The spelling of 2666691878 in words is "two billion, six hundred sixty-six million, six hundred ninety-one thousand, eight hundred seventy-eight".