66196181 has 16 divisors (see below), whose sum is σ = 72839088. Its totient is φ = 59904000.

The previous prime is 66196127. The next prime is 66196187. The reversal of 66196181 is 18169166.

It can be written as a sum of positive squares in 8 ways, for example, as 13764100 + 52432081 = 3710^2 + 7241^2 .

It is a cyclic number.

It is not a de Polignac number, because 66196181 - 2¹⁴ = 66179797 is a prime.

It is a super-2 number, since 2×66196181² = 8763868757969522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66196187) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50231 + ... + 51531.

It is an arithmetic number, because the mean of its divisors is an integer number (4552443).

Almost surely, 2^66196181 is an apocalyptic number.

It is an amenable number.

66196181 is a deficient number, since it is larger than the sum of its proper divisors (6642907).

66196181 is a wasteful number, since it uses less digits than its factorization.

66196181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1432.

The product of its digits is 15552, while the sum is 38.

The square root of 66196181 is about 8136.1035514551. The cubic root of 66196181 is about 404.5240173512.

The spelling of 66196181 in words is "sixty-six million, one hundred ninety-six thousand, one hundred eighty-one".