21100121134243 has 2 divisors, whose sum is σ = 21100121134244. Its totient is φ = 21100121134242.

The previous prime is 21100121134177. The next prime is 21100121134271. The reversal of 21100121134243 is 34243112100112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21100121134243 is a prime.

It is a super-2 number, since 2×21100121134243² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21100121137243) 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, 10550060567121 + 10550060567122.

It is an arithmetic number, because the mean of its divisors is an integer number (10550060567122).

Almost surely, 2^{21100121134243} is an apocalyptic number.

21100121134243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21100121134243 is an equidigital number, since it uses as much as digits as its factorization.

21100121134243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

Adding to 21100121134243 its reverse (34243112100112), we get a palindrome (55343233234355).

The spelling of 21100121134243 in words is "twenty-one trillion, one hundred billion, one hundred twenty-one million, one hundred thirty-four thousand, two hundred forty-three".