213307211221 has 16 divisors (see below), whose sum is σ = 243477332784. Its totient is φ = 185126805504.

The previous prime is 213307211203. The next prime is 213307211261. The reversal of 213307211221 is 122112703312.

It can be written as a sum of positive squares in 8 ways, for example, as 2521546225 + 210785664996 = 50215^2 + 459114^2 .

It is a cyclic number.

It is not a de Polignac number, because 213307211221 - 2¹³ = 213307203029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213307211261) 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, 278040 + ... + 709873.

It is an arithmetic number, because the mean of its divisors is an integer number (15217333299).

Almost surely, 2^213307211221 is an apocalyptic number.

It is an amenable number.

213307211221 is a deficient number, since it is larger than the sum of its proper divisors (30170121563).

213307211221 is a wasteful number, since it uses less digits than its factorization.

213307211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 988920.

The product of its (nonzero) digits is 1008, while the sum is 25.

Adding to 213307211221 its reverse (122112703312), we get a palindrome (335419914533).

The spelling of 213307211221 in words is "two hundred thirteen billion, three hundred seven million, two hundred eleven thousand, two hundred twenty-one".