66965281 has 4 divisors (see below), whose sum is σ = 67282864. Its totient is φ = 66647700.

The previous prime is 66965279. The next prime is 66965293. The reversal of 66965281 is 18256966.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66965281 - 2¹ = 66965279 is a prime.

It is a super-2 number, since 2×66965281² = 8968697718817922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66965221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 158475 + ... + 158896.

It is an arithmetic number, because the mean of its divisors is an integer number (16820716).

Almost surely, 2^66965281 is an apocalyptic number.

It is an amenable number.

66965281 is a deficient number, since it is larger than the sum of its proper divisors (317583).

66965281 is a wasteful number, since it uses less digits than its factorization.

66965281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317582.

The product of its digits is 155520, while the sum is 43.

The square root of 66965281 is about 8183.2316965854. The cubic root of 66965281 is about 406.0846422571.

The spelling of 66965281 in words is "sixty-six million, nine hundred sixty-five thousand, two hundred eighty-one".