21855734071937 has 2 divisors, whose sum is σ = 21855734071938. Its totient is φ = 21855734071936.

The previous prime is 21855734071837. The next prime is 21855734071957. The reversal of 21855734071937 is 73917043755812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16316720044816 + 5539014027121 = 4039396^2 + 2353511^2 .

It is a cyclic number.

It is not a de Polignac number, because 21855734071937 - 2¹⁴ = 21855734055553 is a prime.

It is a super-2 number, since 2×21855734071937² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21855734071937.

It is not a weakly prime, because it can be changed into another prime (21855734071957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10927867035968 + 10927867035969.

It is an arithmetic number, because the mean of its divisors is an integer number (10927867035969).

Almost surely, 2^{21855734071937} is an apocalyptic number.

It is an amenable number.

21855734071937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21855734071937 is an equidigital number, since it uses as much as digits as its factorization.

21855734071937 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44452800, while the sum is 62.

The spelling of 21855734071937 in words is "twenty-one trillion, eight hundred fifty-five billion, seven hundred thirty-four million, seventy-one thousand, nine hundred thirty-seven".