21111101022173 has 2 divisors, whose sum is σ = 21111101022174. Its totient is φ = 21111101022172.

The previous prime is 21111101022107. The next prime is 21111101022203. The reversal of 21111101022173 is 37122010111112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19863262339684 + 1247838682489 = 4456822^2 + 1117067^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111101022173 - 2¹⁶ = 21111100956637 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111101022103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555550511086 + 10555550511087.

It is an arithmetic number, because the mean of its divisors is an integer number (10555550511087).

Almost surely, 2^{21111101022173} is an apocalyptic number.

It is an amenable number.

21111101022173 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111101022173 is an equidigital number, since it uses as much as digits as its factorization.

21111101022173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 168, while the sum is 23.

Adding to 21111101022173 its reverse (37122010111112), we get a palindrome (58233111133285).

The spelling of 21111101022173 in words is "twenty-one trillion, one hundred eleven billion, one hundred one million, twenty-two thousand, one hundred seventy-three".