21021212110110 has 64 divisors (see below), whose sum is σ = 54555175821312. Its totient is φ = 5163658605056.

The previous prime is 21021212110081. The next prime is 21021212110133. The reversal of 21021212110110 is 1101121212012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21021212110110.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 438466062 + ... + 438514001.

It is an arithmetic number, because the mean of its divisors is an integer number (852424622208).

Almost surely, 2^{21021212110110} is an apocalyptic number.

21021212110110 is an abundant number, since it is smaller than the sum of its proper divisors (33533963711202).

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

21021212110110 is a wasteful number, since it uses less digits than its factorization.

21021212110110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 876980137.

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

Adding to 21021212110110 its reverse (1101121212012), we get a palindrome (22122333322122).

The spelling of 21021212110110 in words is "twenty-one trillion, twenty-one billion, two hundred twelve million, one hundred ten thousand, one hundred ten".