213601221 has 24 divisors (see below), whose sum is σ = 312758784. Its totient is φ = 140466240.

The previous prime is 213601217. The next prime is 213601273. The reversal of 213601221 is 122106312.

It is not a de Polignac number, because 213601221 - 2² = 213601217 is a prime.

It is a super-2 number, since 2×213601221² = 91250963225381682, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 213601194 and 213601203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213601121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 235050 + ... + 235956.

It is an arithmetic number, because the mean of its divisors is an integer number (13031616).

Almost surely, 2^213601221 is an apocalyptic number.

It is an amenable number.

213601221 is a deficient number, since it is larger than the sum of its proper divisors (99157563).

213601221 is a wasteful number, since it uses less digits than its factorization.

213601221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1241 (or 1238 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 213601221 is about 14615.1024970747. The cubic root of 213601221 is about 597.7706351466.

Adding to 213601221 its reverse (122106312), we get a palindrome (335707533).

The spelling of 213601221 in words is "two hundred thirteen million, six hundred one thousand, two hundred twenty-one".