221421424 has 40 divisors (see below), whose sum is σ = 496218240. Its totient is φ = 93747648.

The previous prime is 221421419. The next prime is 221421461. The reversal of 221421424 is 424124122.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 221421395 and 221421404.

It is a congruent 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, 2614 + ... + 21205.

It is an arithmetic number, because the mean of its divisors is an integer number (12405456).

Almost surely, 2^221421424 is an apocalyptic number.

It is an amenable number.

221421424 is an abundant number, since it is smaller than the sum of its proper divisors (274796816).

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

221421424 is a wasteful number, since it uses less digits than its factorization.

221421424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23917 (or 23911 counting only the distinct ones).

The product of its digits is 1024, while the sum is 22.

The square root of 221421424 is about 14880.2360196336. The cubic root of 221421424 is about 604.9784150940.

Adding to 221421424 its reverse (424124122), we get a palindrome (645545546).

The spelling of 221421424 in words is "two hundred twenty-one million, four hundred twenty-one thousand, four hundred twenty-four".