66540611 has 4 divisors (see below), whose sum is σ = 66604272. Its totient is φ = 66476952.

The previous prime is 66540563. The next prime is 66540653. The reversal of 66540611 is 11604566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11604566 = 2 ⋅5802283.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66540611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66540671) 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, 30236 + ... + 32361.

It is an arithmetic number, because the mean of its divisors is an integer number (16651068).

Almost surely, 2^66540611 is an apocalyptic number.

66540611 is a deficient number, since it is larger than the sum of its proper divisors (63661).

66540611 is a wasteful number, since it uses less digits than its factorization.

66540611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63660.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 66540611 is about 8157.2428552790. The cubic root of 66540611 is about 405.2244064491.

The spelling of 66540611 in words is "sixty-six million, five hundred forty thousand, six hundred eleven".