21116143729 has 2 divisors, whose sum is σ = 21116143730. Its totient is φ = 21116143728.

The previous prime is 21116143663. The next prime is 21116143817. The reversal of 21116143729 is 92734161112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19467783729 + 1648360000 = 139527^2 + 40600^2 .

It is a cyclic number.

It is not a de Polignac number, because 21116143729 - 2²⁹ = 20579272817 is a prime.

It is not a weakly prime, because it can be changed into another prime (21116143229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10558071864 + 10558071865.

It is an arithmetic number, because the mean of its divisors is an integer number (10558071865).

Almost surely, 2^21116143729 is an apocalyptic number.

It is an amenable number.

21116143729 is a deficient number, since it is larger than the sum of its proper divisors (1).

21116143729 is an equidigital number, since it uses as much as digits as its factorization.

21116143729 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 37.

The spelling of 21116143729 in words is "twenty-one billion, one hundred sixteen million, one hundred forty-three thousand, seven hundred twenty-nine".