221213106 has 24 divisors (see below), whose sum is σ = 497047824. Its totient is φ = 73737540.

The previous prime is 221213099. The next prime is 221213123. The reversal of 221213106 is 601312122.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 227100 + ... + 228071.

It is an arithmetic number, because the mean of its divisors is an integer number (20710326).

Almost surely, 2^221213106 is an apocalyptic number.

221213106 is an abundant number, since it is smaller than the sum of its proper divisors (275834718).

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

221213106 is an equidigital number, since it uses as much as digits as its factorization.

221213106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455188 (or 455176 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 221213106 is about 14873.2345506954. The cubic root of 221213106 is about 604.7886300300.

Adding to 221213106 its reverse (601312122), we get a palindrome (822525228).

The spelling of 221213106 in words is "two hundred twenty-one million, two hundred thirteen thousand, one hundred six".