20111121021 has 8 divisors (see below), whose sum is σ = 26825680960. Its totient is φ = 13401987552.

The previous prime is 20111121013. The next prime is 20111121047. The reversal of 20111121021 is 12012111102.

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

It is not a de Polignac number, because 20111121021 - 2³ = 20111121013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111120988 and 20111121006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111121001) 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, 1347961 + ... + 1362798.

It is an arithmetic number, because the mean of its divisors is an integer number (3353210120).

Almost surely, 2^20111121021 is an apocalyptic number.

It is an amenable number.

20111121021 is a deficient number, since it is larger than the sum of its proper divisors (6714559939).

20111121021 is a wasteful number, since it uses less digits than its factorization.

20111121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2713235.

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

Adding to 20111121021 its reverse (12012111102), we get a palindrome (32123232123).

The spelling of 20111121021 in words is "twenty billion, one hundred eleven million, one hundred twenty-one thousand, twenty-one".