21111011211 has 16 divisors (see below), whose sum is σ = 28801504800. Its totient is φ = 13750360320.

The previous prime is 21111011189. The next prime is 21111011231. The reversal of 21111011211 is 11211011112.

It is not a de Polignac number, because 21111011211 - 2⁶ = 21111011147 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21111011231) 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, 359850 + ... + 414383.

It is an arithmetic number, because the mean of its divisors is an integer number (1800094050).

Almost surely, 2^21111011211 is an apocalyptic number.

21111011211 is a deficient number, since it is larger than the sum of its proper divisors (7690493589).

21111011211 is a wasteful number, since it uses less digits than its factorization.

21111011211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 774446.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21111011211 its reverse (11211011112), we get a palindrome (32322022323).

Subtracting from 21111011211 its reverse (11211011112), we obtain a palindrome (9900000099).

The spelling of 21111011211 in words is "twenty-one billion, one hundred eleven million, eleven thousand, two hundred eleven".