66713220 has 288 divisors, whose sum is σ = 250967808. Its totient is φ = 14556672.

The previous prime is 66713177. The next prime is 66713221. The reversal of 66713220 is 2231766.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (66713221) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1258714 + ... + 1258766.

It is an arithmetic number, because the mean of its divisors is an integer number (871416).

Almost surely, 2^66713220 is an apocalyptic number.

66713220 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 66713220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125483904).

66713220 is an abundant number, since it is smaller than the sum of its proper divisors (184254588).

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

66713220 is a wasteful number, since it uses less digits than its factorization.

66713220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 66713220 is about 8167.8161095852. The cubic root of 66713220 is about 405.5744933367.

Adding to 66713220 its reverse (2231766), we get a palindrome (68944986).

The spelling of 66713220 in words is "sixty-six million, seven hundred thirteen thousand, two hundred twenty".