221121400 has 24 divisors (see below), whose sum is σ = 514107720. Its totient is φ = 88448480.

The previous prime is 221121391. The next prime is 221121403. The reversal of 221121400 is 4121122.

It is a happy number.

221121400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 5 ways as a sum of consecutive naturals, for example, 552604 + ... + 553003.

It is an arithmetic number, because the mean of its divisors is an integer number (21421155).

Almost surely, 2^221121400 is an apocalyptic number.

221121400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221121400 is an abundant number, since it is smaller than the sum of its proper divisors (292986320).

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

221121400 is a wasteful number, since it uses less digits than its factorization.

221121400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1105623 (or 1105614 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 221121400 is about 14870.1513105953. The cubic root of 221121400 is about 604.7050448497.

Adding to 221121400 its reverse (4121122), we get a palindrome (225242522).

The spelling of 221121400 in words is "two hundred twenty-one million, one hundred twenty-one thousand, four hundred".