66572779 has 16 divisors (see below), whose sum is σ = 84582400. Its totient is φ = 50971680.

The previous prime is 66572773. The next prime is 66572783. The reversal of 66572779 is 97727566.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66572779 - 2³ = 66572771 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66572771) 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 15 ways as a sum of consecutive naturals, for example, 8979 + ... + 14620.

It is an arithmetic number, because the mean of its divisors is an integer number (5286400).

Almost surely, 2^66572779 is an apocalyptic number.

66572779 is a deficient number, since it is larger than the sum of its proper divisors (18009621).

66572779 is a wasteful number, since it uses less digits than its factorization.

66572779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23650.

The product of its digits is 1111320, while the sum is 49.

The square root of 66572779 is about 8159.2143616895. The cubic root of 66572779 is about 405.2896956938.

The spelling of 66572779 in words is "sixty-six million, five hundred seventy-two thousand, seven hundred seventy-nine".