221412321 has 12 divisors (see below), whose sum is σ = 344419348. Its totient is φ = 136253664.

The previous prime is 221412311. The next prime is 221412337. The reversal of 221412321 is 123214122.

It is a happy number.

221412321 is a `hidden beast` number, since 221 + 412 + 32 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 53450721 + 167961600 = 7311^2 + 12960^2 .

It is not a de Polignac number, because 221412321 - 2¹³ = 221404129 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221412294 and 221412303.

It is not an unprimeable number, because it can be changed into a prime (221412311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 946090 + ... + 946323.

Almost surely, 2^221412321 is an apocalyptic number.

It is an amenable number.

221412321 is a deficient number, since it is larger than the sum of its proper divisors (123007027).

221412321 is a wasteful number, since it uses less digits than its factorization.

221412321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1892432 (or 1892429 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 221412321 is about 14879.9301409650. The cubic root of 221412321 is about 604.9701244269.

Adding to 221412321 its reverse (123214122), we get a palindrome (344626443).

It can be divided in two parts, 2214123 and 21, that added together give a square (2214144 = 1488²).

The spelling of 221412321 in words is "two hundred twenty-one million, four hundred twelve thousand, three hundred twenty-one".