66583261 has 2 divisors, whose sum is σ = 66583262. Its totient is φ = 66583260.

The previous prime is 66583259. The next prime is 66583289. The reversal of 66583261 is 16238566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 57851236 + 8732025 = 7606^2 + 2955^2 .

It is a cyclic number.

It is not a de Polignac number, because 66583261 - 2¹ = 66583259 is a prime.

Together with 66583259, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 66583261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66583241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33291630 + 33291631.

It is an arithmetic number, because the mean of its divisors is an integer number (33291631).

Almost surely, 2^66583261 is an apocalyptic number.

It is an amenable number.

66583261 is a deficient number, since it is larger than the sum of its proper divisors (1).

66583261 is an equidigital number, since it uses as much as digits as its factorization.

66583261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 51840, while the sum is 37.

The square root of 66583261 is about 8159.8566776629. The cubic root of 66583261 is about 405.3109657670.

The spelling of 66583261 in words is "sixty-six million, five hundred eighty-three thousand, two hundred sixty-one".