20021001111 has 12 divisors (see below), whose sum is σ = 29591764488. Its totient is φ = 13036930704.

The previous prime is 20021001079. The next prime is 20021001139. The reversal of 20021001111 is 11110012002.

It is a happy number.

It is not a de Polignac number, because 20021001111 - 2⁵ = 20021001079 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 20021001093 and 20021001102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021001151) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 25866540 + ... + 25867313.

It is an arithmetic number, because the mean of its divisors is an integer number (2465980374).

Almost surely, 2^20021001111 is an apocalyptic number.

20021001111 is a deficient number, since it is larger than the sum of its proper divisors (9570763377).

20021001111 is a wasteful number, since it uses less digits than its factorization.

20021001111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51733902 (or 51733899 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 20021001111 its reverse (11110012002), we get a palindrome (31131013113).

The spelling of 20021001111 in words is "twenty billion, twenty-one million, one thousand, one hundred eleven".