66181959 has 24 divisors (see below), whose sum is σ = 101861760. Its totient is φ = 41286672.

The previous prime is 66181957. The next prime is 66181981. The reversal of 66181959 is 95918166.

It is not a de Polignac number, because 66181959 - 2¹ = 66181957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66181957) 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 23 ways as a sum of consecutive naturals, for example, 11862 + ... + 16524.

It is an arithmetic number, because the mean of its divisors is an integer number (4244240).

Almost surely, 2^66181959 is an apocalyptic number.

66181959 is a deficient number, since it is larger than the sum of its proper divisors (35679801).

66181959 is a wasteful number, since it uses less digits than its factorization.

66181959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4771 (or 4768 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 66181959 is about 8135.2294989140. The cubic root of 66181959 is about 404.4950451227.

The spelling of 66181959 in words is "sixty-six million, one hundred eighty-one thousand, nine hundred fifty-nine".