221242401 has 16 divisors (see below), whose sum is σ = 328067520. Its totient is φ = 147359520.

The previous prime is 221242337. The next prime is 221242409. The reversal of 221242401 is 104242122.

221242401 is a `hidden beast` number, since 2 + 21 + 242 + 401 = 666.

221242401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221242401 - 2⁶ = 221242337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221242409) 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, 32566 + ... + 38768.

It is an arithmetic number, because the mean of its divisors is an integer number (20504220).

Almost surely, 2^221242401 is an apocalyptic number.

It is an amenable number.

221242401 is a deficient number, since it is larger than the sum of its proper divisors (106825119).

221242401 is a wasteful number, since it uses less digits than its factorization.

221242401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7533 (or 7527 counting only the distinct ones).

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

The square root of 221242401 is about 14874.2193408595. The cubic root of 221242401 is about 604.8153260084.

Adding to 221242401 its reverse (104242122), we get a palindrome (325484523).

The spelling of 221242401 in words is "two hundred twenty-one million, two hundred forty-two thousand, four hundred one".