215031220 has 24 divisors (see below), whose sum is σ = 451871784. Its totient is φ = 85954176.

The previous prime is 215031217. The next prime is 215031233. The reversal of 215031220 is 22130512.

215031220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 54552996 + 160478224 = 7386^2 + 12668^2 .

It is a junction number, because it is equal to n+sod(n) for n = 215031194 and 215031203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38442 + ... + 43678.

It is an arithmetic number, because the mean of its divisors is an integer number (18827991).

Almost surely, 2^215031220 is an apocalyptic number.

215031220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215031220 is an abundant number, since it is smaller than the sum of its proper divisors (236840564).

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

215031220 is a wasteful number, since it uses less digits than its factorization.

215031220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7299 (or 7297 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 215031220 is about 14663.9428531347. The cubic root of 215031220 is about 599.1016370595.

Adding to 215031220 its reverse (22130512), we get a palindrome (237161732).

The spelling of 215031220 in words is "two hundred fifteen million, thirty-one thousand, two hundred twenty".