21021212110985 has 16 divisors (see below), whose sum is σ = 25532899164864. Its totient is φ = 16612062530112.

The previous prime is 21021212110981. The next prime is 21021212110999. The reversal of 21021212110985 is 58901121212012.

It is a cyclic number.

It is not a de Polignac number, because 21021212110985 - 2² = 21021212110981 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021212110981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 481907 + ... + 6501896.

It is an arithmetic number, because the mean of its divisors is an integer number (1595806197804).

Almost surely, 2^{21021212110985} is an apocalyptic number.

It is an amenable number.

21021212110985 is a deficient number, since it is larger than the sum of its proper divisors (4511687053879).

21021212110985 is an equidigital number, since it uses as much as digits as its factorization.

21021212110985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6991144.

The product of its (nonzero) digits is 5760, while the sum is 35.

Adding to 21021212110985 its reverse (58901121212012), we get a palindrome (79922333322997).

The spelling of 21021212110985 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, one hundred ten thousand, nine hundred eighty-five".