21020120112111 has 4 divisors (see below), whose sum is σ = 28026826816152. Its totient is φ = 14013413408072.

The previous prime is 21020120112077. The next prime is 21020120112127. The reversal of 21020120112111 is 11121102102012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21020120112111 - 2²² = 21020115917807 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020120112151) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3503353352016 + ... + 3503353352021.

It is an arithmetic number, because the mean of its divisors is an integer number (7006706704038).

Almost surely, 2^{21020120112111} is an apocalyptic number.

21020120112111 is a deficient number, since it is larger than the sum of its proper divisors (7006706704041).

21020120112111 is an equidigital number, since it uses as much as digits as its factorization.

21020120112111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7006706704040.

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

Adding to 21020120112111 its reverse (11121102102012), we get a palindrome (32141222214123).

The spelling of 21020120112111 in words is "twenty-one trillion, twenty billion, one hundred twenty million, one hundred twelve thousand, one hundred eleven".