221346521 has 8 divisors (see below), whose sum is σ = 243069888. Its totient is φ = 199890000.

The previous prime is 221346509. The next prime is 221346527. The reversal of 221346521 is 125643122.

It is a happy number.

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 221346521 - 2²² = 217152217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221346527) 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, 64970 + ... + 68291.

It is an arithmetic number, because the mean of its divisors is an integer number (30383736).

Almost surely, 2^221346521 is an apocalyptic number.

It is an amenable number.

221346521 is a deficient number, since it is larger than the sum of its proper divisors (21723367).

221346521 is a wasteful number, since it uses less digits than its factorization.

221346521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133423.

The product of its digits is 2880, while the sum is 26.

The square root of 221346521 is about 14877.7189447845. The cubic root of 221346521 is about 604.9101895236.

Adding to 221346521 its reverse (125643122), we get a palindrome (346989643).

The spelling of 221346521 in words is "two hundred twenty-one million, three hundred forty-six thousand, five hundred twenty-one".