66724440 has 32 divisors (see below), whose sum is σ = 200173680. Its totient is φ = 17793152.

The previous prime is 66724421. The next prime is 66724453. The reversal of 66724440 is 4442766.

66724440 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 an unprimeable number.

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, 277899 + ... + 278138.

Almost surely, 2^66724440 is an apocalyptic number.

66724440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66724440 is an abundant number, since it is smaller than the sum of its proper divisors (133449240).

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

66724440 is a wasteful number, since it uses less digits than its factorization.

66724440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556051 (or 556047 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 33.

The square root of 66724440 is about 8168.5029228127. The cubic root of 66724440 is about 405.5972289141.

The spelling of 66724440 in words is "sixty-six million, seven hundred twenty-four thousand, four hundred forty".