66163220 has 12 divisors (see below), whose sum is σ = 138942804. Its totient is φ = 26465280.

The previous prime is 66163219. The next prime is 66163231. The reversal of 66163220 is 2236166.

It can be written as a sum of positive squares in 2 ways, for example, as 19678096 + 46485124 = 4436^2 + 6818^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66163220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1654061 + ... + 1654100.

It is an arithmetic number, because the mean of its divisors is an integer number (11578567).

Almost surely, 2^66163220 is an apocalyptic number.

It is an amenable number.

66163220 is an abundant number, since it is smaller than the sum of its proper divisors (72779584).

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

66163220 is a wasteful number, since it uses less digits than its factorization.

66163220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3308170 (or 3308168 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 66163220 is about 8134.0776981782. The cubic root of 66163220 is about 404.4568647874.

Adding to 66163220 its reverse (2236166), we get a palindrome (68399386).

The spelling of 66163220 in words is "sixty-six million, one hundred sixty-three thousand, two hundred twenty".