21031005067181 has 2 divisors, whose sum is σ = 21031005067182. Its totient is φ = 21031005067180.

The previous prime is 21031005067147. The next prime is 21031005067183. The reversal of 21031005067181 is 18176050013012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18968995226281 + 2062009840900 = 4355341^2 + 1435970^2 .

It is a cyclic number.

It is not a de Polignac number, because 21031005067181 - 2⁶ = 21031005067117 is a prime.

It is a super-2 number, since 2×21031005067181² (a number of 27 digits) contains 22 as substring.

Together with 21031005067183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21031005067183) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10515502533590 + 10515502533591.

It is an arithmetic number, because the mean of its divisors is an integer number (10515502533591).

Almost surely, 2^{21031005067181} is an apocalyptic number.

It is an amenable number.

21031005067181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21031005067181 is an equidigital number, since it uses as much as digits as its factorization.

21031005067181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 35.

The spelling of 21031005067181 in words is "twenty-one trillion, thirty-one billion, five million, sixty-seven thousand, one hundred eighty-one".