21000211211211 has 16 divisors (see below), whose sum is σ = 29259968421120. Its totient is φ = 13372059206880.

The previous prime is 21000211211167. The next prime is 21000211211237. The reversal of 21000211211211 is 11211211200012.

It is a happy number.

It is not a de Polignac number, because 21000211211211 - 2¹³ = 21000211203019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21000211211251) 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, 220177276 + ... + 220272633.

It is an arithmetic number, because the mean of its divisors is an integer number (1828748026320).

Almost surely, 2^{21000211211211} is an apocalyptic number.

21000211211211 is a deficient number, since it is larger than the sum of its proper divisors (8259757209909).

21000211211211 is a wasteful number, since it uses less digits than its factorization.

21000211211211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440450626.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21000211211211 its reverse (11211211200012), we get a palindrome (32211422411223).

The spelling of 21000211211211 in words is "twenty-one trillion, two hundred eleven million, two hundred eleven thousand, two hundred eleven".