166215220 has 24 divisors (see below), whose sum is σ = 352445184. Its totient is φ = 65839776.

The previous prime is 166215209. The next prime is 166215221. The reversal of 166215220 is 22512661.

166215220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166215221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38284 + ... + 42403.

It is an arithmetic number, because the mean of its divisors is an integer number (14685216).

Almost surely, 2^166215220 is an apocalyptic number.

166215220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166215220 is an abundant number, since it is smaller than the sum of its proper divisors (186229964).

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

166215220 is a wasteful number, since it uses less digits than its factorization.

166215220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80799 (or 80797 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 166215220 is about 12892.4481771307. The cubic root of 166215220 is about 549.8238774919.

Adding to 166215220 its reverse (22512661), we get a palindrome (188727881).

The spelling of 166215220 in words is "one hundred sixty-six million, two hundred fifteen thousand, two hundred twenty".