66431140 has 48 divisors (see below), whose sum is σ = 145474560. Its totient is φ = 25453440.

The previous prime is 66431119. The next prime is 66431143. The reversal of 66431140 is 4113466.

It is not an unprimeable number, because it can be changed into a prime (66431143) 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, 67089 + ... + 68071.

It is an arithmetic number, because the mean of its divisors is an integer number (3030720).

Almost surely, 2^66431140 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66431140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72737280).

66431140 is an abundant number, since it is smaller than the sum of its proper divisors (79043420).

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

66431140 is a wasteful number, since it uses less digits than its factorization.

66431140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132 (or 1130 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 66431140 is about 8150.5300441137. The cubic root of 66431140 is about 405.0020626832.

The spelling of 66431140 in words is "sixty-six million, four hundred thirty-one thousand, one hundred forty".