21000202087 has 2 divisors, whose sum is σ = 21000202088. Its totient is φ = 21000202086.

The previous prime is 21000202043. The next prime is 21000202133. The reversal of 21000202087 is 78020200012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000202087 - 2¹⁹ = 20999677799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000202007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500101043 + 10500101044.

It is an arithmetic number, because the mean of its divisors is an integer number (10500101044).

Almost surely, 2^21000202087 is an apocalyptic number.

21000202087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000202087 is an equidigital number, since it uses as much as digits as its factorization.

21000202087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 22.

Adding to 21000202087 its reverse (78020200012), we get a palindrome (99020402099).

The spelling of 21000202087 in words is "twenty-one billion, two hundred two thousand, eighty-seven".