66487840 has 48 divisors (see below), whose sum is σ = 165352320. Its totient is φ = 25194240.

The previous prime is 66487829. The next prime is 66487873. The reversal of 66487840 is 4878466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7896 + ... + 13975.

It is an arithmetic number, because the mean of its divisors is an integer number (3444840).

Almost surely, 2^66487840 is an apocalyptic number.

It is an amenable number.

66487840 is an abundant number, since it is smaller than the sum of its proper divisors (98864480).

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

66487840 is a wasteful number, since it uses less digits than its factorization.

66487840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21905 (or 21897 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 43.

The square root of 66487840 is about 8154.0076036266. The cubic root of 66487840 is about 405.1172550803.

It can be divided in two parts, 6 and 6487840, that added together give a palindrome (6487846).

The spelling of 66487840 in words is "sixty-six million, four hundred eighty-seven thousand, eight hundred forty".