21210220111331 has 4 divisors (see below), whose sum is σ = 21244485411000. Its totient is φ = 21175954811664.

The previous prime is 21210220111321. The next prime is 21210220111337. The reversal of 21210220111331 is 13311102201212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21210220111331 - 2¹⁰ = 21210220110307 is a prime.

It is a super-2 number, since 2×21210220111331² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210220111337) 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, 17132648906 + ... + 17132650143.

It is an arithmetic number, because the mean of its divisors is an integer number (5311121352750).

Almost surely, 2^{21210220111331} is an apocalyptic number.

21210220111331 is a deficient number, since it is larger than the sum of its proper divisors (34265299669).

21210220111331 is an equidigital number, since it uses as much as digits as its factorization.

21210220111331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34265299668.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 21210220111331 its reverse (13311102201212), we get a palindrome (34521322312543).

The spelling of 21210220111331 in words is "twenty-one trillion, two hundred ten billion, two hundred twenty million, one hundred eleven thousand, three hundred thirty-one".