6668810261 has 4 divisors (see below), whose sum is σ = 6669412800. Its totient is φ = 6668207724.

The previous prime is 6668810251. The next prime is 6668810353. The reversal of 6668810261 is 1620188666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1620188666 = 2 ⋅810094333.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6668810261 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6668810221) 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 3 ways as a sum of consecutive naturals, for example, 284351 + ... + 306908.

It is an arithmetic number, because the mean of its divisors is an integer number (1667353200).

Almost surely, 2^6668810261 is an apocalyptic number.

It is an amenable number.

6668810261 is a deficient number, since it is larger than the sum of its proper divisors (602539).

6668810261 is a wasteful number, since it uses less digits than its factorization.

6668810261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602538.

The product of its (nonzero) digits is 165888, while the sum is 44.

The square root of 6668810261 is about 81662.7838185792. The cubic root of 6668810261 is about 1882.2737560955.

The spelling of 6668810261 in words is "six billion, six hundred sixty-eight million, eight hundred ten thousand, two hundred sixty-one".