66522557 has 2 divisors, whose sum is σ = 66522558. Its totient is φ = 66522556.

The previous prime is 66522551. The next prime is 66522569. The reversal of 66522557 is 75522566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46977316 + 19545241 = 6854^2 + 4421^2 .

It is a cyclic number.

It is not a de Polignac number, because 66522557 - 2⁸ = 66522301 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66522557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66522551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33261278 + 33261279.

It is an arithmetic number, because the mean of its divisors is an integer number (33261279).

Almost surely, 2^66522557 is an apocalyptic number.

It is an amenable number.

66522557 is a deficient number, since it is larger than the sum of its proper divisors (1).

66522557 is an equidigital number, since it uses as much as digits as its factorization.

66522557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 126000, while the sum is 38.

The square root of 66522557 is about 8156.1361562936. The cubic root of 66522557 is about 405.1877542298.

Subtracting 66522557 from its reverse (75522566), we obtain a palindrome (9000009).

The spelling of 66522557 in words is "sixty-six million, five hundred twenty-two thousand, five hundred fifty-seven".