21115514653243 has 2 divisors, whose sum is σ = 21115514653244. Its totient is φ = 21115514653242.

The previous prime is 21115514653223. The next prime is 21115514653307. The reversal of 21115514653243 is 34235641551112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21115514653243 - 2⁴¹ = 18916491397691 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21115514653243.

It is not a weakly prime, because it can be changed into another prime (21115514653223) 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, 10557757326621 + 10557757326622.

It is an arithmetic number, because the mean of its divisors is an integer number (10557757326622).

Almost surely, 2^{21115514653243} is an apocalyptic number.

21115514653243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115514653243 is an equidigital number, since it uses as much as digits as its factorization.

21115514653243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432000, while the sum is 43.

The spelling of 21115514653243 in words is "twenty-one trillion, one hundred fifteen billion, five hundred fourteen million, six hundred fifty-three thousand, two hundred forty-three".