66532220 has 48 divisors (see below), whose sum is σ = 149869440. Its totient is φ = 24720384.

The previous prime is 66532201. The next prime is 66532241. The reversal of 66532220 is 2223566.

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 66532220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25622 + ... + 28098.

It is an arithmetic number, because the mean of its divisors is an integer number (3122280).

Almost surely, 2^66532220 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 66532220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74934720).

66532220 is an abundant number, since it is smaller than the sum of its proper divisors (83337220).

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

66532220 is a wasteful number, since it uses less digits than its factorization.

66532220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2582 (or 2580 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 26.

The square root of 66532220 is about 8156.7285108676. The cubic root of 66532220 is about 405.2073723357.

Adding to 66532220 its reverse (2223566), we get a palindrome (68755786).

The spelling of 66532220 in words is "sixty-six million, five hundred thirty-two thousand, two hundred twenty".