21301999087 has 2 divisors, whose sum is σ = 21301999088. Its totient is φ = 21301999086.

The previous prime is 21301999067. The next prime is 21301999099. The reversal of 21301999087 is 78099910312.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21301999087 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21301999087.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21301999027) 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, 10650999543 + 10650999544.

It is an arithmetic number, because the mean of its divisors is an integer number (10650999544).

Almost surely, 2^21301999087 is an apocalyptic number.

21301999087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301999087 is an equidigital number, since it uses as much as digits as its factorization.

21301999087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 49.

The spelling of 21301999087 in words is "twenty-one billion, three hundred one million, nine hundred ninety-nine thousand, eighty-seven".