221215106 has 32 divisors (see below), whose sum is σ = 392822400. Its totient is φ = 93372048.

The previous prime is 221215073. The next prime is 221215129. The reversal of 221215106 is 601512122.

It is a super-2 number, since 2×221215106² = 97872246245182472, which contains 22 as substring.

It is a Curzon 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, 43556 + ... + 48368.

It is an arithmetic number, because the mean of its divisors is an integer number (12275700).

Almost surely, 2^221215106 is an apocalyptic number.

221215106 is a deficient number, since it is larger than the sum of its proper divisors (171607294).

221215106 is an equidigital number, since it uses as much as digits as its factorization.

221215106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4903 (or 4889 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 221215106 is about 14873.3017854140. The cubic root of 221215106 is about 604.7904526671.

Adding to 221215106 its reverse (601512122), we get a palindrome (822727228).

The spelling of 221215106 in words is "two hundred twenty-one million, two hundred fifteen thousand, one hundred six".