66875777 has 4 divisors (see below), whose sum is σ = 67565316. Its totient is φ = 66186240.

The previous prime is 66875747. The next prime is 66875779. The reversal of 66875777 is 77757866.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13278736 + 53597041 = 3644^2 + 7321^2 .

It is a cyclic number.

It is not a de Polignac number, because 66875777 - 2¹⁴ = 66859393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66875779) 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, 344624 + ... + 344817.

It is an arithmetic number, because the mean of its divisors is an integer number (16891329).

Almost surely, 2^66875777 is an apocalyptic number.

It is an amenable number.

66875777 is a deficient number, since it is larger than the sum of its proper divisors (689539).

66875777 is an equidigital number, since it uses as much as digits as its factorization.

66875777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689538.

The product of its digits is 3457440, while the sum is 53.

The square root of 66875777 is about 8177.7611239263. The cubic root of 66875777 is about 405.9036409759.

The spelling of 66875777 in words is "sixty-six million, eight hundred seventy-five thousand, seven hundred seventy-seven".