221121404 has 24 divisors (see below), whose sum is σ = 457494240. Its totient is φ = 91498176.

The previous prime is 221121403. The next prime is 221121413. The reversal of 221121404 is 404121122.

221121404 is digitally balanced in base 3 and base 9, because in such bases it contains all the possibile digits an equal number of times.

221121404 is strictly pandigital in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221121403) 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, 135347 + ... + 136970.

It is an arithmetic number, because the mean of its divisors is an integer number (19062260).

Almost surely, 2^221121404 is an apocalyptic number.

It is an amenable number.

221121404 is an abundant number, since it is smaller than the sum of its proper divisors (236372836).

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

221121404 is a wasteful number, since it uses less digits than its factorization.

221121404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272357 (or 272355 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 221121404 is about 14870.1514450930. The cubic root of 221121404 is about 604.7050484960.

Adding to 221121404 its reverse (404121122), we get a palindrome (625242526).

The spelling of 221121404 in words is "two hundred twenty-one million, one hundred twenty-one thousand, four hundred four".