66601947257 has 2 divisors, whose sum is σ = 66601947258. Its totient is φ = 66601947256.

The previous prime is 66601947239. The next prime is 66601947271. The reversal of 66601947257 is 75274910666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59404800361 + 7197146896 = 243731^2 + 84836^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66601947257 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66601947199 and 66601947208.

It is not a weakly prime, because it can be changed into another prime (66601947277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33300973628 + 33300973629.

It is an arithmetic number, because the mean of its divisors is an integer number (33300973629).

Almost surely, 2^66601947257 is an apocalyptic number.

It is an amenable number.

66601947257 is a deficient number, since it is larger than the sum of its proper divisors (1).

66601947257 is an equidigital number, since it uses as much as digits as its factorization.

66601947257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3810240, while the sum is 53.

The spelling of 66601947257 in words is "sixty-six billion, six hundred one million, nine hundred forty-seven thousand, two hundred fifty-seven".