21143333231 has 2 divisors, whose sum is σ = 21143333232. Its totient is φ = 21143333230.

The previous prime is 21143333153. The next prime is 21143333249. The reversal of 21143333231 is 13233334112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21143333231 is a prime.

It is a super-2 number, since 2×21143333231² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21143333231.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21143333251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571666615 + 10571666616.

It is an arithmetic number, because the mean of its divisors is an integer number (10571666616).

Almost surely, 2^21143333231 is an apocalyptic number.

21143333231 is a deficient number, since it is larger than the sum of its proper divisors (1).

21143333231 is an equidigital number, since it uses as much as digits as its factorization.

21143333231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 26.

Adding to 21143333231 its reverse (13233334112), we get a palindrome (34376667343).

The spelling of 21143333231 in words is "twenty-one billion, one hundred forty-three million, three hundred thirty-three thousand, two hundred thirty-one".