221405412 has 24 divisors (see below), whose sum is σ = 529214112. Its totient is φ = 72001600.

The previous prime is 221405407. The next prime is 221405413. The reversal of 221405412 is 214504122.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (221405413) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 224514 + ... + 225497.

It is an arithmetic number, because the mean of its divisors is an integer number (22050588).

Almost surely, 2^221405412 is an apocalyptic number.

It is an amenable number.

221405412 is an abundant number, since it is smaller than the sum of its proper divisors (307808700).

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

221405412 is a wasteful number, since it uses less digits than its factorization.

221405412 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450059 (or 450057 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 21.

The square root of 221405412 is about 14879.6979808059. The cubic root of 221405412 is about 604.9638318200.

Adding to 221405412 its reverse (214504122), we get a palindrome (435909534).

The spelling of 221405412 in words is "two hundred twenty-one million, four hundred five thousand, four hundred twelve".