66195861 has 8 divisors (see below), whose sum is σ = 88364640. Its totient is φ = 44078832.

The previous prime is 66195859. The next prime is 66195911. The reversal of 66195861 is 16859166.

It is a happy number.

66195861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66195861 - 2¹ = 66195859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66195821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9846 + ... + 15143.

It is an arithmetic number, because the mean of its divisors is an integer number (11045580).

Almost surely, 2^66195861 is an apocalyptic number.

It is an amenable number.

66195861 is a deficient number, since it is larger than the sum of its proper divisors (22168779).

66195861 is a wasteful number, since it uses less digits than its factorization.

66195861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25875.

The product of its digits is 77760, while the sum is 42.

The square root of 66195861 is about 8136.0838859982. The cubic root of 66195861 is about 404.5233655115.

The spelling of 66195861 in words is "sixty-six million, one hundred ninety-five thousand, eight hundred sixty-one".