666530779 has 4 divisors (see below), whose sum is σ = 666587880. Its totient is φ = 666473680.

The previous prime is 666530771. The next prime is 666530797. The reversal of 666530779 is 977035666.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 977035666 = 2 ⋅488517833.

It is a cyclic number.

It is not a de Polignac number, because 666530779 - 2³ = 666530771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666530771) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4009 + ... + 36730.

It is an arithmetic number, because the mean of its divisors is an integer number (166646970).

Almost surely, 2^666530779 is an apocalyptic number.

666530779 is a deficient number, since it is larger than the sum of its proper divisors (57101).

666530779 is a wasteful number, since it uses less digits than its factorization.

666530779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57100.

The product of its (nonzero) digits is 1428840, while the sum is 49.

The square root of 666530779 is about 25817.2573872594. The cubic root of 666530779 is about 873.5211062976.

The spelling of 666530779 in words is "six hundred sixty-six million, five hundred thirty thousand, seven hundred seventy-nine".