215299220 has 54 divisors (see below), whose sum is σ = 482790042. Its totient is φ = 80633856.

The previous prime is 215299213. The next prime is 215299243. The reversal of 215299220 is 22992512.

It can be written as a sum of positive squares in 9 ways, for example, as 38887696 + 176411524 = 6236^2 + 13282^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 1115444 + ... + 1115636.

Almost surely, 2^215299220 is an apocalyptic number.

215299220 is a gapful number since it is divisible by the number (20) 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 215299220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241395021).

215299220 is an abundant number, since it is smaller than the sum of its proper divisors (267490822).

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

215299220 is a wasteful number, since it uses less digits than its factorization.

215299220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 429 (or 217 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 215299220 is about 14673.0780683536. The cubic root of 215299220 is about 599.3504266408.

Multiplying 215299220 by its product of nonzero digits (6480), we get a square (1395138945600 = 1181160²).

The spelling of 215299220 in words is "two hundred fifteen million, two hundred ninety-nine thousand, two hundred twenty".