66427951 has 4 divisors (see below), whose sum is σ = 68718600. Its totient is φ = 64137304.

The previous prime is 66427939. The next prime is 66427969. The reversal of 66427951 is 15972466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15972466 = 2 ⋅7986233.

It is a cyclic number.

It is not a de Polignac number, because 66427951 - 2⁵ = 66427919 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66427901) 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, 1145281 + ... + 1145338.

It is an arithmetic number, because the mean of its divisors is an integer number (17179650).

Almost surely, 2^66427951 is an apocalyptic number.

66427951 is a deficient number, since it is larger than the sum of its proper divisors (2290649).

66427951 is a wasteful number, since it uses less digits than its factorization.

66427951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2290648.

The product of its digits is 90720, while the sum is 40.

The square root of 66427951 is about 8150.3344103172. The cubic root of 66427951 is about 404.9955819261.

The spelling of 66427951 in words is "sixty-six million, four hundred twenty-seven thousand, nine hundred fifty-one".