21011221022087 has 2 divisors, whose sum is σ = 21011221022088. Its totient is φ = 21011221022086.

The previous prime is 21011221022063. The next prime is 21011221022089. The reversal of 21011221022087 is 78022012211012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21011221022087 - 2³⁶ = 20942501545351 is a prime.

Together with 21011221022089, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21011221022089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505610511043 + 10505610511044.

It is an arithmetic number, because the mean of its divisors is an integer number (10505610511044).

Almost surely, 2^{21011221022087} is an apocalyptic number.

21011221022087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21011221022087 is an equidigital number, since it uses as much as digits as its factorization.

21011221022087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1792, while the sum is 29.

Adding to 21011221022087 its reverse (78022012211012), we get a palindrome (99033233233099).

The spelling of 21011221022087 in words is "twenty-one trillion, eleven billion, two hundred twenty-one million, twenty-two thousand, eighty-seven".