66323440 has 40 divisors (see below), whose sum is σ = 154655280. Its totient is φ = 26451456.

The previous prime is 66323417. The next prime is 66323461. The reversal of 66323440 is 4432366.

66323440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 66323399 and 66323408.

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, 31707 + ... + 33733.

It is an arithmetic number, because the mean of its divisors is an integer number (3866382).

Almost surely, 2^66323440 is an apocalyptic number.

It is an amenable number.

66323440 is an abundant number, since it is smaller than the sum of its proper divisors (88331840).

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

66323440 is a wasteful number, since it uses less digits than its factorization.

66323440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2449 (or 2443 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 28.

The square root of 66323440 is about 8143.9204318313. The cubic root of 66323440 is about 404.7830774535.

The spelling of 66323440 in words is "sixty-six million, three hundred twenty-three thousand, four hundred forty".