66135640 has 32 divisors (see below), whose sum is σ = 150696000. Its totient is φ = 26118144.

The previous prime is 66135611. The next prime is 66135647. The reversal of 66135640 is 4653166.

66135640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66135647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7305 + ... + 13624.

It is an arithmetic number, because the mean of its divisors is an integer number (4709250).

Almost surely, 2^66135640 is an apocalyptic number.

It is an amenable number.

66135640 is an abundant number, since it is smaller than the sum of its proper divisors (84560360).

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

66135640 is a wasteful number, since it uses less digits than its factorization.

66135640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21019 (or 21015 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 66135640 is about 8132.3821848214. The cubic root of 66135640 is about 404.4006579771.

The spelling of 66135640 in words is "sixty-six million, one hundred thirty-five thousand, six hundred forty".