21120012011121 has 8 divisors (see below), whose sum is σ = 29816487545184. Its totient is φ = 13251772242240.

The previous prime is 21120012010991. The next prime is 21120012011129. The reversal of 21120012011121 is 12111021002112.

It is a happy number.

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

It is not a de Polignac number, because 21120012011121 - 2¹⁴ = 21120011994737 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21120012011121.

It is not an unprimeable number, because it can be changed into a prime (21120012011129) 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, 207058941235 + ... + 207058941336.

It is an arithmetic number, because the mean of its divisors is an integer number (3727060943148).

Almost surely, 2^{21120012011121} is an apocalyptic number.

It is an amenable number.

21120012011121 is a deficient number, since it is larger than the sum of its proper divisors (8696475534063).

21120012011121 is a wasteful number, since it uses less digits than its factorization.

21120012011121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414117882591.

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

Adding to 21120012011121 its reverse (12111021002112), we get a palindrome (33231033013233).

The spelling of 21120012011121 in words is "twenty-one trillion, one hundred twenty billion, twelve million, eleven thousand, one hundred twenty-one".