66724729 has 2 divisors, whose sum is σ = 66724730. Its totient is φ = 66724728.

The previous prime is 66724717. The next prime is 66724747. The reversal of 66724729 is 92742766.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66585600 + 139129 = 8160^2 + 373^2 .

It is a cyclic number.

It is not a de Polignac number, because 66724729 - 2⁷ = 66724601 is a prime.

It is not a weakly prime, because it can be changed into another prime (66724709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33362364 + 33362365.

It is an arithmetic number, because the mean of its divisors is an integer number (33362365).

Almost surely, 2^66724729 is an apocalyptic number.

It is an amenable number.

66724729 is a deficient number, since it is larger than the sum of its proper divisors (1).

66724729 is an equidigital number, since it uses as much as digits as its factorization.

66724729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 254016, while the sum is 43.

The square root of 66724729 is about 8168.5206126936. The cubic root of 66724729 is about 405.5978144938.

The spelling of 66724729 in words is "sixty-six million, seven hundred twenty-four thousand, seven hundred twenty-nine".