21120122121 has 8 divisors (see below), whose sum is σ = 32183043264. Its totient is φ = 12068641200.

The previous prime is 21120122119. The next prime is 21120122129. The reversal of 21120122121 is 12122102112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21120122121 - 2¹ = 21120122119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21120122121.

It is not an unprimeable number, because it can be changed into a prime (21120122129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 502860030 + ... + 502860071.

It is an arithmetic number, because the mean of its divisors is an integer number (4022880408).

Almost surely, 2^21120122121 is an apocalyptic number.

21120122121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21120122121 is a deficient number, since it is larger than the sum of its proper divisors (11062921143).

21120122121 is a wasteful number, since it uses less digits than its factorization.

21120122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1005720111.

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

Adding to 21120122121 its reverse (12122102112), we get a palindrome (33242224233).

The spelling of 21120122121 in words is "twenty-one billion, one hundred twenty million, one hundred twenty-two thousand, one hundred twenty-one".