21012222220987 has 2 divisors, whose sum is σ = 21012222220988. Its totient is φ = 21012222220986.

The previous prime is 21012222220861. The next prime is 21012222221027. The reversal of 21012222220987 is 78902222221012.

It is an a-pointer prime, because the next prime (21012222221027) can be obtained adding 21012222220987 to its sum of digits (40).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21012222220987 - 2¹⁹ = 21012221696699 is a prime.

It is not a weakly prime, because it can be changed into another prime (21012222220687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506111110493 + 10506111110494.

It is an arithmetic number, because the mean of its divisors is an integer number (10506111110494).

Almost surely, 2^{21012222220987} is an apocalyptic number.

21012222220987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012222220987 is an equidigital number, since it uses as much as digits as its factorization.

21012222220987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 40.

Adding to 21012222220987 its reverse (78902222221012), we get a palindrome (99914444441999).

The spelling of 21012222220987 in words is "twenty-one trillion, twelve billion, two hundred twenty-two million, two hundred twenty thousand, nine hundred eighty-seven".