66338181 has 48 divisors (see below), whose sum is σ = 119193984. Its totient is φ = 34618752.

The previous prime is 66338161. The next prime is 66338183. The reversal of 66338181 is 18183366.

66338181 is a `hidden beast` number, since 6 + 633 + 8 + 18 + 1 = 666.

It is not a de Polignac number, because 66338181 - 2⁹ = 66337669 is a prime.

It is a super-2 number, since 2×66338181² = 8801508516777522, which contains 22 as substring.

66338181 is a modest number, since divided by 8181 gives 6633 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66338183) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 87255 + ... + 88011.

It is an arithmetic number, because the mean of its divisors is an integer number (2483208).

Almost surely, 2^66338181 is an apocalyptic number.

It is an amenable number.

66338181 is a deficient number, since it is larger than the sum of its proper divisors (52855803).

66338181 is a wasteful number, since it uses less digits than its factorization.

66338181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890 (or 887 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 66338181 is about 8144.8254124935. The cubic root of 66338181 is about 404.8130641637.

The spelling of 66338181 in words is "sixty-six million, three hundred thirty-eight thousand, one hundred eighty-one".