21111221143 has 2 divisors, whose sum is σ = 21111221144. Its totient is φ = 21111221142.

The previous prime is 21111221141. The next prime is 21111221167. The reversal of 21111221143 is 34112211112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21111221143 - 2¹ = 21111221141 is a prime.

Together with 21111221141, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21111221143.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111221141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555610571 + 10555610572.

It is an arithmetic number, because the mean of its divisors is an integer number (10555610572).

Almost surely, 2^21111221143 is an apocalyptic number.

21111221143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111221143 is an equidigital number, since it uses as much as digits as its factorization.

21111221143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 19.

Adding to 21111221143 its reverse (34112211112), we get a palindrome (55223432255).

The spelling of 21111221143 in words is "twenty-one billion, one hundred eleven million, two hundred twenty-one thousand, one hundred forty-three".