21337755161 has 2 divisors, whose sum is σ = 21337755162. Its totient is φ = 21337755160.

The previous prime is 21337755157. The next prime is 21337755191. The reversal of 21337755161 is 16155773312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12060212761 + 9277542400 = 109819^2 + 96320^2 .

It is a cyclic number.

It is not a de Polignac number, because 21337755161 - 2² = 21337755157 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21337755191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10668877580 + 10668877581.

It is an arithmetic number, because the mean of its divisors is an integer number (10668877581).

Almost surely, 2^21337755161 is an apocalyptic number.

It is an amenable number.

21337755161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21337755161 is an equidigital number, since it uses as much as digits as its factorization.

21337755161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 132300, while the sum is 41.

The spelling of 21337755161 in words is "twenty-one billion, three hundred thirty-seven million, seven hundred fifty-five thousand, one hundred sixty-one".