221221146 has 16 divisors (see below), whose sum is σ = 456715008. Its totient is φ = 71361600.

The previous prime is 221221127. The next prime is 221221213. The reversal of 221221146 is 641122122.

221221146 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 594495 + ... + 594866.

It is an arithmetic number, because the mean of its divisors is an integer number (28544688).

Almost surely, 2^221221146 is an apocalyptic number.

221221146 is an abundant number, since it is smaller than the sum of its proper divisors (235493862).

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

221221146 is a wasteful number, since it uses less digits than its factorization.

221221146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189397.

The product of its digits is 384, while the sum is 21.

The square root of 221221146 is about 14873.5048324193. The cubic root of 221221146 is about 604.7959569643.

Adding to 221221146 its reverse (641122122), we get a palindrome (862343268).

The spelling of 221221146 in words is "two hundred twenty-one million, two hundred twenty-one thousand, one hundred forty-six".