221422401 has 12 divisors (see below), whose sum is σ = 323000340. Its totient is φ = 146152800.

The previous prime is 221422379. The next prime is 221422417. The reversal of 221422401 is 104224122.

221422401 is a `hidden beast` number, since 221 + 42 + 2 + 401 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 100400400 + 121022001 = 10020^2 + 11001^2 .

It is not a de Polignac number, because 221422401 - 2¹⁰ = 221421377 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221422001) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 120886 + ... + 122703.

It is an arithmetic number, because the mean of its divisors is an integer number (26916695).

Almost surely, 2^221422401 is an apocalyptic number.

It is an amenable number.

221422401 is a deficient number, since it is larger than the sum of its proper divisors (101577939).

221422401 is a wasteful number, since it uses less digits than its factorization.

221422401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 243696 (or 243693 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 221422401 is about 14880.2688483777. The cubic root of 221422401 is about 604.9793048951.

Adding to 221422401 its reverse (104224122), we get a palindrome (325646523).

The spelling of 221422401 in words is "two hundred twenty-one million, four hundred twenty-two thousand, four hundred one".