66770251 has 2 divisors, whose sum is σ = 66770252. Its totient is φ = 66770250.

The previous prime is 66770243. The next prime is 66770261. The reversal of 66770251 is 15207766.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66770251 - 2³ = 66770243 is a prime.

It is not a weakly prime, because it can be changed into another prime (66770201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33385125 + 33385126.

It is an arithmetic number, because the mean of its divisors is an integer number (33385126).

Almost surely, 2^66770251 is an apocalyptic number.

66770251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66770251 is an equidigital number, since it uses as much as digits as its factorization.

66770251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 66770251 is about 8171.3065662720. The cubic root of 66770251 is about 405.6900313112.

The spelling of 66770251 in words is "sixty-six million, seven hundred seventy thousand, two hundred fifty-one".