66171240 has 48 divisors (see below), whose sum is σ = 215057700. Its totient is φ = 17645568.

The previous prime is 66171227. The next prime is 66171241. The reversal of 66171240 is 4217166.

66171240 is a `hidden beast` number, since 6 + 617 + 1 + 2 + 40 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 61685316 + 4485924 = 7854^2 + 2118^2 .

It is not an unprimeable number, because it can be changed into a prime (66171241) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 91545 + ... + 92264.

Almost surely, 2^66171240 is an apocalyptic number.

66171240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66171240 is an abundant number, since it is smaller than the sum of its proper divisors (148886460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66171240 is a wasteful number, since it uses less digits than its factorization.

66171240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183826 (or 183819 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 66171240 is about 8134.5706709082. The cubic root of 66171240 is about 404.4732062583.

The spelling of 66171240 in words is "sixty-six million, one hundred seventy-one thousand, two hundred forty".