20021121111 has 8 divisors (see below), whose sum is σ = 26699146864. Its totient is φ = 13345254720.

The previous prime is 20021121061. The next prime is 20021121137. The reversal of 20021121111 is 11112112002.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20021121111 - 2²⁵ = 19987566679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021121011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518080 + ... + 555381.

It is an arithmetic number, because the mean of its divisors is an integer number (3337393358).

Almost surely, 2^20021121111 is an apocalyptic number.

20021121111 is a deficient number, since it is larger than the sum of its proper divisors (6678025753).

20021121111 is a wasteful number, since it uses less digits than its factorization.

20021121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1079681.

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

Adding to 20021121111 its reverse (11112112002), we get a palindrome (31133233113).

The spelling of 20021121111 in words is "twenty billion, twenty-one million, one hundred twenty-one thousand, one hundred eleven".