221400421 has 16 divisors (see below), whose sum is σ = 248371200. Its totient is φ = 195617520.

The previous prime is 221400379. The next prime is 221400437. The reversal of 221400421 is 124004122.

221400421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 221400421 - 2¹⁹ = 220876133 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221400395 and 221400404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221400121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104430 + ... + 106528.

It is an arithmetic number, because the mean of its divisors is an integer number (15523200).

Almost surely, 2^221400421 is an apocalyptic number.

It is an amenable number.

221400421 is a deficient number, since it is larger than the sum of its proper divisors (26970779).

221400421 is a wasteful number, since it uses less digits than its factorization.

221400421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2376.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 221400421 is about 14879.5302681234. The cubic root of 221400421 is about 604.9592860155.

Adding to 221400421 its reverse (124004122), we get a palindrome (345404543).

The spelling of 221400421 in words is "two hundred twenty-one million, four hundred thousand, four hundred twenty-one".