20111211021 has 16 divisors (see below), whose sum is σ = 30973416768. Its totient is φ = 11471635200.

The previous prime is 20111211019. The next prime is 20111211031. The reversal of 20111211021 is 12011211102.

It is not a de Polignac number, because 20111211021 - 2¹ = 20111211019 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20111210988 and 20111211006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111211011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17923870 + ... + 17924991.

It is an arithmetic number, because the mean of its divisors is an integer number (1935838548).

Almost surely, 2^20111211021 is an apocalyptic number.

It is an amenable number.

20111211021 is a deficient number, since it is larger than the sum of its proper divisors (10862205747).

20111211021 is a wasteful number, since it uses less digits than its factorization.

20111211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35848892.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20111211021 its reverse (12011211102), we get a palindrome (32122422123).

It can be divided in two parts, 20111 and 211021, that added together give a palindrome (231132).

The spelling of 20111211021 in words is "twenty billion, one hundred eleven million, two hundred eleven thousand, twenty-one".