21300020087 has 2 divisors, whose sum is σ = 21300020088. Its totient is φ = 21300020086.

The previous prime is 21300020083. The next prime is 21300020117. The reversal of 21300020087 is 78002000312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21300020087 - 2² = 21300020083 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21300020083) 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, 10650010043 + 10650010044.

It is an arithmetic number, because the mean of its divisors is an integer number (10650010044).

Almost surely, 2^21300020087 is an apocalyptic number.

21300020087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21300020087 is an equidigital number, since it uses as much as digits as its factorization.

21300020087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 23.

Adding to 21300020087 its reverse (78002000312), we get a palindrome (99302020399).

The spelling of 21300020087 in words is "twenty-one billion, three hundred million, twenty thousand, eighty-seven".