11431043021 has 4 divisors (see below), whose sum is σ = 11646723132. Its totient is φ = 11215362912.

The previous prime is 11431043011. The next prime is 11431043023. The reversal of 11431043021 is 12034013411.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10143309796 + 1287733225 = 100714^2 + 35885^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11431043021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11431042984 and 11431043002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11431043023) 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, 107839976 + ... + 107840081.

It is an arithmetic number, because the mean of its divisors is an integer number (2911680783).

Almost surely, 2^11431043021 is an apocalyptic number.

It is an amenable number.

11431043021 is a deficient number, since it is larger than the sum of its proper divisors (215680111).

11431043021 is an equidigital number, since it uses as much as digits as its factorization.

11431043021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215680110.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 11431043021 its reverse (12034013411), we get a palindrome (23465056432).

The spelling of 11431043021 in words is "eleven billion, four hundred thirty-one million, forty-three thousand, twenty-one".