66508231 has 2 divisors, whose sum is σ = 66508232. Its totient is φ = 66508230.

The previous prime is 66508213. The next prime is 66508271. The reversal of 66508231 is 13280566.

Together with previous prime (66508213) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66508231 - 2¹⁹ = 65983943 is a prime.

It is a super-2 number, since 2×66508231² = 8846689581498722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 66508193 and 66508202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66508201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33254115 + 33254116.

It is an arithmetic number, because the mean of its divisors is an integer number (33254116).

Almost surely, 2^66508231 is an apocalyptic number.

66508231 is a deficient number, since it is larger than the sum of its proper divisors (1).

66508231 is an equidigital number, since it uses as much as digits as its factorization.

66508231 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 66508231 is about 8155.2578745249. The cubic root of 66508231 is about 405.1586656681.

Adding to 66508231 its reverse (13280566), we get a palindrome (79788797).

The spelling of 66508231 in words is "sixty-six million, five hundred eight thousand, two hundred thirty-one".