66323840 has 64 divisors (see below), whose sum is σ = 172987920. Its totient is φ = 24115200.

The previous prime is 66323837. The next prime is 66323857. The reversal of 66323840 is 4832366.

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

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 66323797 and 66323806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2330 + ... + 11750.

Almost surely, 2^66323840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66323840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86493960).

66323840 is an abundant number, since it is smaller than the sum of its proper divisors (106664080).

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

66323840 is a wasteful number, since it uses less digits than its factorization.

66323840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9451 (or 9439 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 66323840 is about 8143.9449899910. The cubic root of 66323840 is about 404.7838912075.

The spelling of 66323840 in words is "sixty-six million, three hundred twenty-three thousand, eight hundred forty".