21936039887 has 2 divisors, whose sum is σ = 21936039888. Its totient is φ = 21936039886.

The previous prime is 21936039863. The next prime is 21936039893. The reversal of 21936039887 is 78893063912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21936039887 - 2¹⁴ = 21936023503 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21936039857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10968019943 + 10968019944.

It is an arithmetic number, because the mean of its divisors is an integer number (10968019944).

Almost surely, 2^21936039887 is an apocalyptic number.

21936039887 is a deficient number, since it is larger than the sum of its proper divisors (1).

21936039887 is an equidigital number, since it uses as much as digits as its factorization.

21936039887 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3919104, while the sum is 56.

The spelling of 21936039887 in words is "twenty-one billion, nine hundred thirty-six million, thirty-nine thousand, eight hundred eighty-seven".