21173136003121 has 2 divisors, whose sum is σ = 21173136003122. Its totient is φ = 21173136003120.

The previous prime is 21173136003091. The next prime is 21173136003127. The reversal of 21173136003121 is 12130063137112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12509909194225 + 8663226808896 = 3536935^2 + 2943336^2 .

It is a cyclic number.

It is not a de Polignac number, because 21173136003121 - 2²⁵ = 21173102448689 is a prime.

It is not a weakly prime, because it can be changed into another prime (21173136003127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10586568001560 + 10586568001561.

It is an arithmetic number, because the mean of its divisors is an integer number (10586568001561).

Almost surely, 2^{21173136003121} is an apocalyptic number.

It is an amenable number.

21173136003121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21173136003121 is an equidigital number, since it uses as much as digits as its factorization.

21173136003121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 31.

The spelling of 21173136003121 in words is "twenty-one trillion, one hundred seventy-three billion, one hundred thirty-six million, three thousand, one hundred twenty-one".