221144021 has 8 divisors (see below), whose sum is σ = 266038080. Its totient is φ = 179575488.

The previous prime is 221144017. The next prime is 221144023. The reversal of 221144021 is 120441122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 221144021 - 2² = 221144017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221144023) 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, 831236 + ... + 831501.

It is an arithmetic number, because the mean of its divisors is an integer number (33254760).

Almost surely, 2^221144021 is an apocalyptic number.

It is an amenable number.

221144021 is a deficient number, since it is larger than the sum of its proper divisors (44894059).

221144021 is a wasteful number, since it uses less digits than its factorization.

221144021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662763.

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

The square root of 221144021 is about 14870.9119088239. The cubic root of 221144021 is about 604.7256648445.

Adding to 221144021 its reverse (120441122), we get a palindrome (341585143).

The spelling of 221144021 in words is "two hundred twenty-one million, one hundred forty-four thousand, twenty-one".