66140081 has 16 divisors (see below), whose sum is σ = 82621440. Its totient is φ = 51632640.

The previous prime is 66140077. The next prime is 66140101. The reversal of 66140081 is 18004166.

It is a cyclic number.

It is not a de Polignac number, because 66140081 - 2² = 66140077 is a prime.

It is a super-2 number, since 2×66140081² = 8749020629373122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66140081.

It is not an unprimeable number, because it can be changed into a prime (66140071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5276 + ... + 12653.

It is an arithmetic number, because the mean of its divisors is an integer number (5163840).

Almost surely, 2^66140081 is an apocalyptic number.

It is an amenable number.

66140081 is a deficient number, since it is larger than the sum of its proper divisors (16481359).

66140081 is a wasteful number, since it uses less digits than its factorization.

66140081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17984.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 66140081 is about 8132.6552244639. The cubic root of 66140081 is about 404.4097095925.

The spelling of 66140081 in words is "sixty-six million, one hundred forty thousand, eighty-one".