20100111021 has 24 divisors (see below), whose sum is σ = 29182200320. Its totient is φ = 13331519136.

The previous prime is 20100111013. The next prime is 20100111067. The reversal of 20100111021 is 12011100102.

It is a happy number.

It is not a de Polignac number, because 20100111021 - 2³ = 20100111013 is a prime.

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

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20100110994 and 20100111012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100111011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5792475 + ... + 5795943.

Almost surely, 2^20100111021 is an apocalyptic number.

It is an amenable number.

20100111021 is a deficient number, since it is larger than the sum of its proper divisors (9082089299).

20100111021 is a wasteful number, since it uses less digits than its factorization.

20100111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6585 (or 6582 counting only the distinct ones).

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

Adding to 20100111021 its reverse (12011100102), we get a palindrome (32111211123).

The spelling of 20100111021 in words is "twenty billion, one hundred million, one hundred eleven thousand, twenty-one".