20021021111 has 16 divisors (see below), whose sum is σ = 24644660544. Its totient is φ = 15838619904.

The previous prime is 20021021093. The next prime is 20021021177. The reversal of 20021021111 is 11112012002.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021021111 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20021021092 and 20021021101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021020111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1073381 + ... + 1091873.

It is an arithmetic number, because the mean of its divisors is an integer number (1540291284).

Almost surely, 2^20021021111 is an apocalyptic number.

20021021111 is a deficient number, since it is larger than the sum of its proper divisors (4623639433).

20021021111 is a wasteful number, since it uses less digits than its factorization.

20021021111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30410.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 20021021111 its reverse (11112012002), we get a palindrome (31133033113).

The spelling of 20021021111 in words is "twenty billion, twenty-one million, twenty-one thousand, one hundred eleven".