21124100087 has 2 divisors, whose sum is σ = 21124100088. Its totient is φ = 21124100086.

The previous prime is 21124100027. The next prime is 21124100089. The reversal of 21124100087 is 78000142112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21124100087 - 2⁸ = 21124099831 is a prime.

Together with 21124100089, 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 (21124100089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562050043 + 10562050044.

It is an arithmetic number, because the mean of its divisors is an integer number (10562050044).

Almost surely, 2^21124100087 is an apocalyptic number.

21124100087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124100087 is an equidigital number, since it uses as much as digits as its factorization.

21124100087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 26.

Adding to 21124100087 its reverse (78000142112), we get a palindrome (99124242199).

The spelling of 21124100087 in words is "twenty-one billion, one hundred twenty-four million, one hundred thousand, eighty-seven".