221215020 has 48 divisors (see below), whose sum is σ = 667050720. Its totient is φ = 54452736.

The previous prime is 221215019. The next prime is 221215031. The reversal of 221215020 is 20512122.

It is a Harshad number since it is a multiple of its sum of digits (15).

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, 141025 + ... + 142584.

It is an arithmetic number, because the mean of its divisors is an integer number (13896890).

Almost surely, 2^221215020 is an apocalyptic number.

221215020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221215020 is an abundant number, since it is smaller than the sum of its proper divisors (445835700).

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

221215020 is a wasteful number, since it uses less digits than its factorization.

221215020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283634 (or 283632 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 221215020 is about 14873.2988943274. The cubic root of 221215020 is about 604.7903742939.

Adding to 221215020 its reverse (20512122), we get a palindrome (241727142).

The spelling of 221215020 in words is "two hundred twenty-one million, two hundred fifteen thousand, twenty".