66264840 has 192 divisors, whose sum is σ = 230480640. Its totient is φ = 16473600.

The previous prime is 66264791. The next prime is 66264881. The reversal of 66264840 is 4846266.

It is a happy number.

66264840 is a `hidden beast` number, since 6 + 6 + 2 + 648 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66264795 and 66264804.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 438765 + ... + 438915.

It is an arithmetic number, because the mean of its divisors is an integer number (1200420).

Almost surely, 2^66264840 is an apocalyptic number.

66264840 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 66264840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115240320).

66264840 is an abundant number, since it is smaller than the sum of its proper divisors (164215800).

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

66264840 is a wasteful number, since it uses less digits than its factorization.

66264840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 66264840 is about 8140.3218609586. The cubic root of 66264840 is about 404.6638271161.

The spelling of 66264840 in words is "sixty-six million, two hundred sixty-four thousand, eight hundred forty".