66733440 has 64 divisors (see below), whose sum is σ = 212718960. Its totient is φ = 17795072.

The previous prime is 66733409. The next prime is 66733441. The reversal of 66733440 is 4433766.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66733441) 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, 15459 + ... + 19298.

Almost surely, 2^66733440 is an apocalyptic number.

66733440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66733440 is an abundant number, since it is smaller than the sum of its proper divisors (145985520).

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

66733440 is a wasteful number, since it uses less digits than its factorization.

66733440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34779 (or 34767 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 33.

The square root of 66733440 is about 8169.0538007777. The cubic root of 66733440 is about 405.6154641661.

The spelling of 66733440 in words is "sixty-six million, seven hundred thirty-three thousand, four hundred forty".