66552220 has 48 divisors (see below), whose sum is σ = 162364608. Its totient is φ = 22440960.

The previous prime is 66552217. The next prime is 66552221. The reversal of 66552220 is 2225566.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66552221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4644 + ... + 12436.

It is an arithmetic number, because the mean of its divisors is an integer number (3382596).

Almost surely, 2^66552220 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 66552220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81182304).

66552220 is an abundant number, since it is smaller than the sum of its proper divisors (95812388).

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

66552220 is a wasteful number, since it uses less digits than its factorization.

66552220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7870 (or 7868 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 66552220 is about 8157.9544004609. The cubic root of 66552220 is about 405.2479708885.

Adding to 66552220 its reverse (2225566), we get a palindrome (68777786).

The spelling of 66552220 in words is "sixty-six million, five hundred fifty-two thousand, two hundred twenty".