21031212221113 has 4 divisors (see below), whose sum is σ = 21031229410048. Its totient is φ = 21031195032180.

The previous prime is 21031212221093. The next prime is 21031212221141. The reversal of 21031212221113 is 31112221213012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21031212221113 - 2¹³ = 21031212212921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031212221213) 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, 6605781 + ... + 9257362.

It is an arithmetic number, because the mean of its divisors is an integer number (5257807352512).

Almost surely, 2^{21031212221113} is an apocalyptic number.

It is an amenable number.

21031212221113 is a deficient number, since it is larger than the sum of its proper divisors (17188935).

21031212221113 is a wasteful number, since it uses less digits than its factorization.

21031212221113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17188934.

The product of its (nonzero) digits is 288, while the sum is 22.

Adding to 21031212221113 its reverse (31112221213012), we get a palindrome (52143433434125).

It can be divided in two parts, 2103121 and 2221113, that added together give a palindrome (4324234).

The spelling of 21031212221113 in words is "twenty-one trillion, thirty-one billion, two hundred twelve million, two hundred twenty-one thousand, one hundred thirteen".