21210222111 has 16 divisors (see below), whose sum is σ = 30479078784. Its totient is φ = 13042426464.

The previous prime is 21210222073. The next prime is 21210222113. The reversal of 21210222111 is 11122201212.

It is not a de Polignac number, because 21210222111 - 2²⁶ = 21143113247 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210222113) 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, 157081 + ... + 259026.

It is an arithmetic number, because the mean of its divisors is an integer number (1904942424).

Almost surely, 2^21210222111 is an apocalyptic number.

21210222111 is a deficient number, since it is larger than the sum of its proper divisors (9268856673).

21210222111 is a wasteful number, since it uses less digits than its factorization.

21210222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417430.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21210222111 its reverse (11122201212), we get a palindrome (32332423323).

The spelling of 21210222111 in words is "twenty-one billion, two hundred ten million, two hundred twenty-two thousand, one hundred eleven".