66023729 has 4 divisors (see below), whose sum is σ = 66704484. Its totient is φ = 65342976.

The previous prime is 66023719. The next prime is 66023747. The reversal of 66023729 is 92732066.

It is a happy number.

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 52591504 + 13432225 = 7252^2 + 3665^2 .

It is a cyclic number.

It is not a de Polignac number, because 66023729 - 2²⁴ = 49246513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66023719) 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, 340232 + ... + 340425.

It is an arithmetic number, because the mean of its divisors is an integer number (16676121).

Almost surely, 2^66023729 is an apocalyptic number.

It is an amenable number.

66023729 is a deficient number, since it is larger than the sum of its proper divisors (680755).

66023729 is an equidigital number, since it uses as much as digits as its factorization.

66023729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680754.

The product of its (nonzero) digits is 27216, while the sum is 35.

The square root of 66023729 is about 8125.4986923881. The cubic root of 66023729 is about 404.1724278675.

It can be divided in two parts, 660 and 23729, that added together give a cube (24389 = 29³).

The spelling of 66023729 in words is "sixty-six million, twenty-three thousand, seven hundred twenty-nine".