66729761 has 4 divisors (see below), whose sum is σ = 76262592. Its totient is φ = 57196932.

The previous prime is 66729757. The next prime is 66729779. The reversal of 66729761 is 16792766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16792766 = 2 ⋅8396383.

It is a cyclic number.

It is not a de Polignac number, because 66729761 - 2² = 66729757 is a prime.

It is a super-2 number, since 2×66729761² = 8905722006234242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66729721) 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, 4766405 + ... + 4766418.

It is an arithmetic number, because the mean of its divisors is an integer number (19065648).

Almost surely, 2^66729761 is an apocalyptic number.

It is an amenable number.

66729761 is a deficient number, since it is larger than the sum of its proper divisors (9532831).

66729761 is an equidigital number, since it uses as much as digits as its factorization.

66729761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9532830.

The product of its digits is 190512, while the sum is 44.

The square root of 66729761 is about 8168.8286185964. The cubic root of 66729761 is about 405.6080101985.

The spelling of 66729761 in words is "sixty-six million, seven hundred twenty-nine thousand, seven hundred sixty-one".