6661660979 has 2 divisors, whose sum is σ = 6661660980. Its totient is φ = 6661660978.

The previous prime is 6661660969. The next prime is 6661660997. The reversal of 6661660979 is 9790661666.

It is a happy number.

Together with next prime (6661660997) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6661660979 - 2²⁰ = 6660612403 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (6661660909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3330830489 + 3330830490.

It is an arithmetic number, because the mean of its divisors is an integer number (3330830490).

Almost surely, 2^6661660979 is an apocalyptic number.

6661660979 is a deficient number, since it is larger than the sum of its proper divisors (1).

6661660979 is an equidigital number, since it uses as much as digits as its factorization.

6661660979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4408992, while the sum is 56.

The square root of 6661660979 is about 81618.9988850635. The cubic root of 6661660979 is about 1881.6008865712.

The spelling of 6661660979 in words is "six billion, six hundred sixty-one million, six hundred sixty thousand, nine hundred seventy-nine".