215131220 has 48 divisors (see below), whose sum is σ = 467389440. Its totient is φ = 83126784.

The previous prime is 215131181. The next prime is 215131253. The reversal of 215131220 is 22131512.

It is a happy number.

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, 72812 + ... + 75708.

It is an arithmetic number, because the mean of its divisors is an integer number (9737280).

Almost surely, 2^215131220 is an apocalyptic number.

215131220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215131220 is an abundant number, since it is smaller than the sum of its proper divisors (252258220).

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

215131220 is a wasteful number, since it uses less digits than its factorization.

215131220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3032 (or 3030 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 215131220 is about 14667.3521809494. The cubic root of 215131220 is about 599.1944931559.

Adding to 215131220 its reverse (22131512), we get a palindrome (237262732).

The spelling of 215131220 in words is "two hundred fifteen million, one hundred thirty-one thousand, two hundred twenty".