213126221 has 16 divisors (see below), whose sum is σ = 266502528. Its totient is φ = 165580800.

The previous prime is 213126187. The next prime is 213126227. The reversal of 213126221 is 122621312.

It is not a de Polignac number, because 213126221 - 2⁶ = 213126157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 213126193 and 213126202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213126227) 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, 23261 + ... + 31101.

It is an arithmetic number, because the mean of its divisors is an integer number (16656408).

Almost surely, 2^213126221 is an apocalyptic number.

It is an amenable number.

213126221 is a deficient number, since it is larger than the sum of its proper divisors (53376307).

213126221 is a wasteful number, since it uses less digits than its factorization.

213126221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8212.

The product of its digits is 288, while the sum is 20.

The square root of 213126221 is about 14598.8431390984. The cubic root of 213126221 is about 597.3272048079.

Adding to 213126221 its reverse (122621312), we get a palindrome (335747533).

The spelling of 213126221 in words is "two hundred thirteen million, one hundred twenty-six thousand, two hundred twenty-one".