21861171939583 has 2 divisors, whose sum is σ = 21861171939584. Its totient is φ = 21861171939582.

The previous prime is 21861171939577. The next prime is 21861171939613. The reversal of 21861171939583 is 38593917116812.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21861171939583 is a prime.

It is a super-2 number, since 2×21861171939583² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21861171939083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10930585969791 + 10930585969792.

It is an arithmetic number, because the mean of its divisors is an integer number (10930585969792).

Almost surely, 2^{21861171939583} is an apocalyptic number.

21861171939583 is a deficient number, since it is larger than the sum of its proper divisors (1).

21861171939583 is an equidigital number, since it uses as much as digits as its factorization.

21861171939583 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 19595520, while the sum is 64.

The spelling of 21861171939583 in words is "twenty-one trillion, eight hundred sixty-one billion, one hundred seventy-one million, nine hundred thirty-nine thousand, five hundred eighty-three".