66662549 has 2 divisors, whose sum is σ = 66662550. Its totient is φ = 66662548.

The previous prime is 66662509. The next prime is 66662551. The reversal of 66662549 is 94526666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54538225 + 12124324 = 7385^2 + 3482^2 .

It is a cyclic number.

It is not a de Polignac number, because 66662549 - 2⁸ = 66662293 is a prime.

It is a Sophie Germain prime.

Together with 66662551, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66662509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33331274 + 33331275.

It is an arithmetic number, because the mean of its divisors is an integer number (33331275).

Almost surely, 2^66662549 is an apocalyptic number.

It is an amenable number.

66662549 is a deficient number, since it is larger than the sum of its proper divisors (1).

66662549 is an equidigital number, since it uses as much as digits as its factorization.

66662549 is an evil number, because the sum of its binary digits is even.

The product of its digits is 466560, while the sum is 44.

The square root of 66662549 is about 8164.7136508270. The cubic root of 66662549 is about 405.4717847062.

The spelling of 66662549 in words is "sixty-six million, six hundred sixty-two thousand, five hundred forty-nine".