21012320143 has 2 divisors, whose sum is σ = 21012320144. Its totient is φ = 21012320142.

The previous prime is 21012320117. The next prime is 21012320159. The reversal of 21012320143 is 34102321012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21012320143 - 2¹⁷ = 21012189071 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21012320143.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012320743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506160071 + 10506160072.

It is an arithmetic number, because the mean of its divisors is an integer number (10506160072).

Almost surely, 2^21012320143 is an apocalyptic number.

21012320143 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012320143 is an equidigital number, since it uses as much as digits as its factorization.

21012320143 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21012320143 its reverse (34102321012), we get a palindrome (55114641155).

The spelling of 21012320143 in words is "twenty-one billion, twelve million, three hundred twenty thousand, one hundred forty-three".