66397320 has 288 divisors, whose sum is σ = 255078720. Its totient is φ = 15396480.

The previous prime is 66397313. The next prime is 66397333. The reversal of 66397320 is 2379366.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2886829 + ... + 2886851.

It is an arithmetic number, because the mean of its divisors is an integer number (885690).

Almost surely, 2^66397320 is an apocalyptic number.

66397320 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 66397320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (127539360).

66397320 is an abundant number, since it is smaller than the sum of its proper divisors (188681400).

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

66397320 is a wasteful number, since it uses less digits than its factorization.

66397320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 44 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 36.

The square root of 66397320 is about 8148.4550682936. The cubic root of 66397320 is about 404.9333223564.

It can be divided in two parts, 66 and 397320, that added together give a triangular number (397386 = T₈₉₁).

The spelling of 66397320 in words is "sixty-six million, three hundred ninety-seven thousand, three hundred twenty".