21011113213231 has 4 divisors (see below), whose sum is σ = 21014040782512. Its totient is φ = 21008185643952.

The previous prime is 21011113213213. The next prime is 21011113213273. The reversal of 21011113213231 is 13231231111012.

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 21011113213231 - 2¹¹ = 21011113211183 is a prime.

It is a super-2 number, since 2×21011113213231² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011113213291) 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, 1463773875 + ... + 1463788228.

It is an arithmetic number, because the mean of its divisors is an integer number (5253510195628).

Almost surely, 2^{21011113213231} is an apocalyptic number.

21011113213231 is a deficient number, since it is larger than the sum of its proper divisors (2927569281).

21011113213231 is an equidigital number, since it uses as much as digits as its factorization.

21011113213231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2927569280.

The product of its (nonzero) digits is 216, while the sum is 22.

Adding to 21011113213231 its reverse (13231231111012), we get a palindrome (34242344324243).

The spelling of 21011113213231 in words is "twenty-one trillion, eleven billion, one hundred thirteen million, two hundred thirteen thousand, two hundred thirty-one".