66768081 has 4 divisors (see below), whose sum is σ = 89024112. Its totient is φ = 44512052.

The previous prime is 66768077. The next prime is 66768089. The reversal of 66768081 is 18086766.

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 66768081 - 2² = 66768077 is a prime.

It is a super-2 number, since 2×66768081² = 8915953280845122, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66768089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11128011 + ... + 11128016.

It is an arithmetic number, because the mean of its divisors is an integer number (22256028).

Almost surely, 2^66768081 is an apocalyptic number.

It is an amenable number.

66768081 is a deficient number, since it is larger than the sum of its proper divisors (22256031).

66768081 is a wasteful number, since it uses less digits than its factorization.

66768081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22256030.

The product of its (nonzero) digits is 96768, while the sum is 42.

The square root of 66768081 is about 8171.1737834903. The cubic root of 66768081 is about 405.6856363554.

The spelling of 66768081 in words is "sixty-six million, seven hundred sixty-eight thousand, eighty-one".