20011211111121 has 4 divisors (see below), whose sum is σ = 26681614814832. Its totient is φ = 13340807407412.

The previous prime is 20011211111107. The next prime is 20011211111123. The reversal of 20011211111121 is 12111111211002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20011211111121 - 2⁶ = 20011211111057 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 20011211111121.

It is not an unprimeable number, because it can be changed into a prime (20011211111123) 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, 3335201851851 + ... + 3335201851856.

It is an arithmetic number, because the mean of its divisors is an integer number (6670403703708).

Almost surely, 2^{20011211111121} is an apocalyptic number.

It is an amenable number.

20011211111121 is a deficient number, since it is larger than the sum of its proper divisors (6670403703711).

20011211111121 is an equidigital number, since it uses as much as digits as its factorization.

20011211111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6670403703710.

The product of its (nonzero) digits is 8, while the sum is 15.

Adding to 20011211111121 its reverse (12111111211002), we get a palindrome (32122322322123).

The spelling of 20011211111121 in words is "twenty trillion, eleven billion, two hundred eleven million, one hundred eleven thousand, one hundred twenty-one".