21508331927 has 2 divisors, whose sum is σ = 21508331928. Its totient is φ = 21508331926.

The previous prime is 21508331921. The next prime is 21508331989. The reversal of 21508331927 is 72913380512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21508331927 - 2⁸ = 21508331671 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21508331921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10754165963 + 10754165964.

It is an arithmetic number, because the mean of its divisors is an integer number (10754165964).

Almost surely, 2^21508331927 is an apocalyptic number.

21508331927 is a deficient number, since it is larger than the sum of its proper divisors (1).

21508331927 is an equidigital number, since it uses as much as digits as its factorization.

21508331927 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 21508331927 in words is "twenty-one billion, five hundred eight million, three hundred thirty-one thousand, nine hundred twenty-seven".