21221211112110 has 64 divisors (see below), whose sum is σ = 57150192375360. Its totient is φ = 5602960022400.

The previous prime is 21221211112097. The next prime is 21221211112181. The reversal of 21221211112110 is 1121111212212.

It is a happy number.

21221211112110 is a `hidden beast` number, since 21 + 221 + 211 + 1 + 1 + 211 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 389067177 + ... + 389121716.

It is an arithmetic number, because the mean of its divisors is an integer number (892971755865).

Almost surely, 2^{21221211112110} is an apocalyptic number.

21221211112110 is an abundant number, since it is smaller than the sum of its proper divisors (35928981263250).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221211112110 is a wasteful number, since it uses less digits than its factorization.

21221211112110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778189010 (or 778189004 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21221211112110 its reverse (1121111212212), we get a palindrome (22342322324322).

The spelling of 21221211112110 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred twelve thousand, one hundred ten".