21220123213 has 16 divisors (see below), whose sum is σ = 21566290176. Its totient is φ = 20877337600.

The previous prime is 21220123207. The next prime is 21220123237. The reversal of 21220123213 is 31232102212.

It is not a de Polignac number, because 21220123213 - 2¹⁷ = 21219992141 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 (21220123283) 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, 10285020 + ... + 10287082.

It is an arithmetic number, because the mean of its divisors is an integer number (1347893136).

Almost surely, 2^21220123213 is an apocalyptic number.

It is an amenable number.

21220123213 is a deficient number, since it is larger than the sum of its proper divisors (346166963).

21220123213 is a wasteful number, since it uses less digits than its factorization.

21220123213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2804.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21220123213 its reverse (31232102212), we get a palindrome (52452225425).

The spelling of 21220123213 in words is "twenty-one billion, two hundred twenty million, one hundred twenty-three thousand, two hundred thirteen".