66573840 has 80 divisors (see below), whose sum is σ = 207415296. Its totient is φ = 17664000.

The previous prime is 66573827. The next prime is 66573851. The reversal of 66573840 is 4837566.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 57265 + ... + 58415.

Almost surely, 2^66573840 is an apocalyptic number.

66573840 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66573840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103707648).

66573840 is an abundant number, since it is smaller than the sum of its proper divisors (140841456).

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

66573840 is a wasteful number, since it uses less digits than its factorization.

66573840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408 (or 1402 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 39.

The square root of 66573840 is about 8159.2793799453. The cubic root of 66573840 is about 405.2918487764.

The spelling of 66573840 in words is "sixty-six million, five hundred seventy-three thousand, eight hundred forty".