66464257 has 2 divisors, whose sum is σ = 66464258. Its totient is φ = 66464256.

The previous prime is 66464243. The next prime is 66464263. The reversal of 66464257 is 75246466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64625521 + 1838736 = 8039^2 + 1356^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66464257 is a prime.

It is not a weakly prime, because it can be changed into another prime (66464207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33232128 + 33232129.

It is an arithmetic number, because the mean of its divisors is an integer number (33232129).

Almost surely, 2^66464257 is an apocalyptic number.

It is an amenable number.

66464257 is a deficient number, since it is larger than the sum of its proper divisors (1).

66464257 is an equidigital number, since it uses as much as digits as its factorization.

66464257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 40.

The square root of 66464257 is about 8152.5613766472. The cubic root of 66464257 is about 405.0693515337.

The spelling of 66464257 in words is "sixty-six million, four hundred sixty-four thousand, two hundred fifty-seven".