21181158121271 has 4 divisors (see below), whose sum is σ = 21386800433232. Its totient is φ = 20975515809312.

The previous prime is 21181158121267. The next prime is 21181158121273. The reversal of 21181158121271 is 17212185118112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21181158121271 - 2² = 21181158121267 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21181158121273) 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 in 3 ways as a sum of consecutive naturals, for example, 102821155826 + ... + 102821156031.

It is an arithmetic number, because the mean of its divisors is an integer number (5346700108308).

Almost surely, 2^{21181158121271} is an apocalyptic number.

21181158121271 is a deficient number, since it is larger than the sum of its proper divisors (205642311961).

21181158121271 is a wasteful number, since it uses less digits than its factorization.

21181158121271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205642311960.

The product of its digits is 17920, while the sum is 41.

The spelling of 21181158121271 in words is "twenty-one trillion, one hundred eighty-one billion, one hundred fifty-eight million, one hundred twenty-one thousand, two hundred seventy-one".