215121222 has 12 divisors (see below), whose sum is σ = 466096020. Its totient is φ = 71707068.

The previous prime is 215121191. The next prime is 215121229. The reversal of 215121222 is 222121512.

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 11951179 = 215121222 / (2 + 1 + 5 + 1 + 2 + 1 + 2 + 2 + 2).

It is a junction number, because it is equal to n+sod(n) for n = 215121195 and 215121204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215121229) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5975572 + ... + 5975607.

It is an arithmetic number, because the mean of its divisors is an integer number (38841335).

Almost surely, 2^215121222 is an apocalyptic number.

215121222 is an abundant number, since it is smaller than the sum of its proper divisors (250974798).

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

215121222 is a wasteful number, since it uses less digits than its factorization.

215121222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11951187 (or 11951184 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 215121222 is about 14667.0113520103. The cubic root of 215121222 is about 599.1852106982.

Adding to 215121222 its reverse (222121512), we get a palindrome (437242734).

The spelling of 215121222 in words is "two hundred fifteen million, one hundred twenty-one thousand, two hundred twenty-two".