21001231113 has 4 divisors (see below), whose sum is σ = 28001641488. Its totient is φ = 14000820740.

The previous prime is 21001231099. The next prime is 21001231159. The reversal of 21001231113 is 31113210012.

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 a de Polignac number, because none of the positive numbers 2^k-21001231113 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001231092 and 21001231101.

It is not an unprimeable number, because it can be changed into a prime (21001231213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3500205183 + ... + 3500205188.

It is an arithmetic number, because the mean of its divisors is an integer number (7000410372).

Almost surely, 2^21001231113 is an apocalyptic number.

It is an amenable number.

21001231113 is a deficient number, since it is larger than the sum of its proper divisors (7000410375).

21001231113 is an equidigital number, since it uses as much as digits as its factorization.

21001231113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7000410374.

The product of its (nonzero) digits is 36, while the sum is 15.

Adding to 21001231113 its reverse (31113210012), we get a palindrome (52114441125).

The spelling of 21001231113 in words is "twenty-one billion, one million, two hundred thirty-one thousand, one hundred thirteen".