21012021221211 has 16 divisors (see below), whose sum is σ = 31593531081600. Its totient is φ = 13798939308264.

The previous prime is 21012021221179. The next prime is 21012021221249. The reversal of 21012021221211 is 11212212021012.

21012021221211 is a `hidden beast` number, since 210 + 1 + 2 + 0 + 21 + 221 + 211 = 666.

It is not a de Polignac number, because 21012021221211 - 2⁵ = 21012021221179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21012021221911) 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, 5807632581 + ... + 5807636198.

It is an arithmetic number, because the mean of its divisors is an integer number (1974595692600).

Almost surely, 2^{21012021221211} is an apocalyptic number.

21012021221211 is a deficient number, since it is larger than the sum of its proper divisors (10581509860389).

21012021221211 is a wasteful number, since it uses less digits than its factorization.

21012021221211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11615268855 (or 11615268849 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21012021221211 its reverse (11212212021012), we get a palindrome (32224233242223).

The spelling of 21012021221211 in words is "twenty-one trillion, twelve billion, twenty-one million, two hundred twenty-one thousand, two hundred eleven".