66645273 has 4 divisors (see below), whose sum is σ = 88860368. Its totient is φ = 44430180.

The previous prime is 66645259. The next prime is 66645289. The reversal of 66645273 is 37254666.

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 a de Polignac number, because none of the positive numbers 2^k-66645273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66645233) 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, 11107543 + ... + 11107548.

It is an arithmetic number, because the mean of its divisors is an integer number (22215092).

Almost surely, 2^66645273 is an apocalyptic number.

It is an amenable number.

66645273 is a deficient number, since it is larger than the sum of its proper divisors (22215095).

66645273 is a wasteful number, since it uses less digits than its factorization.

66645273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22215094.

The product of its digits is 181440, while the sum is 39.

The square root of 66645273 is about 8163.6556149803. The cubic root of 66645273 is about 405.4367548638.

The spelling of 66645273 in words is "sixty-six million, six hundred forty-five thousand, two hundred seventy-three".