66251243 has 2 divisors, whose sum is σ = 66251244. Its totient is φ = 66251242.

The previous prime is 66251239. The next prime is 66251267. The reversal of 66251243 is 34215266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66251243 - 2² = 66251239 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66251443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33125621 + 33125622.

It is an arithmetic number, because the mean of its divisors is an integer number (33125622).

Almost surely, 2^66251243 is an apocalyptic number.

66251243 is a deficient number, since it is larger than the sum of its proper divisors (1).

66251243 is an equidigital number, since it uses as much as digits as its factorization.

66251243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8640, while the sum is 29.

The square root of 66251243 is about 8139.4866545747. The cubic root of 66251243 is about 404.6361473268.

The spelling of 66251243 in words is "sixty-six million, two hundred fifty-one thousand, two hundred forty-three".