66757440 has 56 divisors (see below), whose sum is σ = 211957920. Its totient is φ = 17801728.

The previous prime is 66757429. The next prime is 66757441. The reversal of 66757440 is 4475766.

66757440 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 (66757441) 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, 33810 + ... + 35729.

Almost surely, 2^66757440 is an apocalyptic number.

66757440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66757440 is an abundant number, since it is smaller than the sum of its proper divisors (145200480).

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

66757440 is a wasteful number, since it uses less digits than its factorization.

66757440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69559 (or 69549 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 39.

The square root of 66757440 is about 8170.5226271029. The cubic root of 66757440 is about 405.6640834909.

The spelling of 66757440 in words is "sixty-six million, seven hundred fifty-seven thousand, four hundred forty".