66724761 has 4 divisors (see below), whose sum is σ = 88966352. Its totient is φ = 44483172.

The previous prime is 66724747. The next prime is 66724769. The reversal of 66724761 is 16742766.

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.

It is not a de Polignac number, because 66724761 - 2⁵ = 66724729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66724769) 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, 11120791 + ... + 11120796.

It is an arithmetic number, because the mean of its divisors is an integer number (22241588).

Almost surely, 2^66724761 is an apocalyptic number.

It is an amenable number.

66724761 is a deficient number, since it is larger than the sum of its proper divisors (22241591).

66724761 is a wasteful number, since it uses less digits than its factorization.

66724761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22241590.

The product of its digits is 84672, while the sum is 39.

The square root of 66724761 is about 8168.5225714324. The cubic root of 66724761 is about 405.5978793329.

The spelling of 66724761 in words is "sixty-six million, seven hundred twenty-four thousand, seven hundred sixty-one".