66140551 has 4 divisors (see below), whose sum is σ = 66328272. Its totient is φ = 65952832.

The previous prime is 66140537. The next prime is 66140563. The reversal of 66140551 is 15504166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66140551 - 2⁵ = 66140519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66140351) 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, 93331 + ... + 94036.

It is an arithmetic number, because the mean of its divisors is an integer number (16582068).

Almost surely, 2^66140551 is an apocalyptic number.

66140551 is a deficient number, since it is larger than the sum of its proper divisors (187721).

66140551 is a wasteful number, since it uses less digits than its factorization.

66140551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187720.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 66140551 is about 8132.6841202644. The cubic root of 66140551 is about 404.4106675195.

The spelling of 66140551 in words is "sixty-six million, one hundred forty thousand, five hundred fifty-one".