20121111121999 has 4 divisors (see below), whose sum is σ = 20121585685336. Its totient is φ = 20120636558664.

The previous prime is 20121111121967. The next prime is 20121111122003. The reversal of 20121111121999 is 99912111112102.

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 20121111121999 - 2⁵ = 20121111121967 is a prime.

It is a super-2 number, since 2×20121111121999² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121111121939) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 237218064 + ... + 237302869.

It is an arithmetic number, because the mean of its divisors is an integer number (5030396421334).

Almost surely, 2^{20121111121999} is an apocalyptic number.

20121111121999 is a deficient number, since it is larger than the sum of its proper divisors (474563337).

20121111121999 is an equidigital number, since it uses as much as digits as its factorization.

20121111121999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474563336.

The product of its (nonzero) digits is 5832, while the sum is 40.

The spelling of 20121111121999 in words is "twenty trillion, one hundred twenty-one billion, one hundred eleven million, one hundred twenty-one thousand, nine hundred ninety-nine".