66511273 has 2 divisors, whose sum is σ = 66511274. Its totient is φ = 66511272.

The previous prime is 66511271. The next prime is 66511279. The reversal of 66511273 is 37211566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66455104 + 56169 = 8152^2 + 237^2 .

It is a cyclic number.

It is not a de Polignac number, because 66511273 - 2¹ = 66511271 is a prime.

Together with 66511271, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (66511271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33255636 + 33255637.

It is an arithmetic number, because the mean of its divisors is an integer number (33255637).

Almost surely, 2^66511273 is an apocalyptic number.

It is an amenable number.

66511273 is a deficient number, since it is larger than the sum of its proper divisors (1).

66511273 is an equidigital number, since it uses as much as digits as its factorization.

66511273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 31.

The square root of 66511273 is about 8155.4443778374. Note that the first 3 decimals coincide. The cubic root of 66511273 is about 405.1648427174.

The spelling of 66511273 in words is "sixty-six million, five hundred eleven thousand, two hundred seventy-three".