213001221 has 4 divisors (see below), whose sum is σ = 284001632. Its totient is φ = 142000812.

The previous prime is 213001213. The next prime is 213001249. The reversal of 213001221 is 122100312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 213001221 - 2³ = 213001213 is a prime.

It is a Duffinian number.

213001221 is a modest number, since divided by 1221 gives 213 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 213001197 and 213001206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213001121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35500201 + ... + 35500206.

It is an arithmetic number, because the mean of its divisors is an integer number (71000408).

Almost surely, 2^213001221 is an apocalyptic number.

It is an amenable number.

213001221 is a deficient number, since it is larger than the sum of its proper divisors (71000411).

213001221 is an equidigital number, since it uses as much as digits as its factorization.

213001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71000410.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 213001221 is about 14594.5613500372. The cubic root of 213001221 is about 597.2104031268.

Adding to 213001221 its reverse (122100312), we get a palindrome (335101533).

Subtracting from 213001221 its reverse (122100312), we obtain a palindrome (90900909).

The spelling of 213001221 in words is "two hundred thirteen million, one thousand, two hundred twenty-one".