66706281 has 8 divisors (see below), whose sum is σ = 98824160. Its totient is φ = 44470836.

The previous prime is 66706271. The next prime is 66706307. The reversal of 66706281 is 18260766.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-66706281 is a prime.

It is a super-2 number, since 2×66706281² = 8899455849701922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66706271) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1235275 + ... + 1235328.

It is an arithmetic number, because the mean of its divisors is an integer number (12353020).

Almost surely, 2^66706281 is an apocalyptic number.

It is an amenable number.

66706281 is a deficient number, since it is larger than the sum of its proper divisors (32117879).

66706281 is a wasteful number, since it uses less digits than its factorization.

66706281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2470612 (or 2470606 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 66706281 is about 8167.3913215910. The cubic root of 66706281 is about 405.5604312613.

The spelling of 66706281 in words is "sixty-six million, seven hundred six thousand, two hundred eighty-one".