66894251 has 2 divisors, whose sum is σ = 66894252. Its totient is φ = 66894250.

The previous prime is 66894241. The next prime is 66894319. The reversal of 66894251 is 15249866.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66894251 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66894199 and 66894208.

It is not a weakly prime, because it can be changed into another prime (66894211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33447125 + 33447126.

It is an arithmetic number, because the mean of its divisors is an integer number (33447126).

Almost surely, 2^66894251 is an apocalyptic number.

66894251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66894251 is an equidigital number, since it uses as much as digits as its factorization.

66894251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 66894251 is about 8178.8905726877. The cubic root of 66894251 is about 405.9410136182.

The spelling of 66894251 in words is "sixty-six million, eight hundred ninety-four thousand, two hundred fifty-one".