66147251 has 2 divisors, whose sum is σ = 66147252. Its totient is φ = 66147250.

The previous prime is 66147247. The next prime is 66147259. The reversal of 66147251 is 15274166.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66147251 - 2² = 66147247 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66147259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33073625 + 33073626.

It is an arithmetic number, because the mean of its divisors is an integer number (33073626).

Almost surely, 2^66147251 is an apocalyptic number.

66147251 is a deficient number, since it is larger than the sum of its proper divisors (1).

66147251 is an equidigital number, since it uses as much as digits as its factorization.

66147251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 32.

The square root of 66147251 is about 8133.0960279588. The cubic root of 66147251 is about 404.4243225816.

The spelling of 66147251 in words is "sixty-six million, one hundred forty-seven thousand, two hundred fifty-one".