21116534177 has 2 divisors, whose sum is σ = 21116534178. Its totient is φ = 21116534176.

The previous prime is 21116534161. The next prime is 21116534189. The reversal of 21116534177 is 77143561112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20575320481 + 541213696 = 143441^2 + 23264^2 .

It is a cyclic number.

It is not a de Polignac number, because 21116534177 - 2⁴ = 21116534161 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21116534177.

It is not a weakly prime, because it can be changed into another prime (21116534977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10558267088 + 10558267089.

It is an arithmetic number, because the mean of its divisors is an integer number (10558267089).

Almost surely, 2^21116534177 is an apocalyptic number.

It is an amenable number.

21116534177 is a deficient number, since it is larger than the sum of its proper divisors (1).

21116534177 is an equidigital number, since it uses as much as digits as its factorization.

21116534177 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 38.

The spelling of 21116534177 in words is "twenty-one billion, one hundred sixteen million, five hundred thirty-four thousand, one hundred seventy-seven".