66012640 has 48 divisors (see below), whose sum is σ = 160997760. Its totient is φ = 25551360.

The previous prime is 66012623. The next prime is 66012641. The reversal of 66012640 is 4621066.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66012641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1695 + ... + 11614.

It is an arithmetic number, because the mean of its divisors is an integer number (3354120).

Almost surely, 2^66012640 is an apocalyptic number.

It is an amenable number.

66012640 is an abundant number, since it is smaller than the sum of its proper divisors (94985120).

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

66012640 is a wasteful number, since it uses less digits than its factorization.

66012640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13355 (or 13347 counting only the distinct ones).

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

The square root of 66012640 is about 8124.8163056158. The cubic root of 66012640 is about 404.1497990386.

The spelling of 66012640 in words is "sixty-six million, twelve thousand, six hundred forty".