20109110021 has 32 divisors (see below), whose sum is σ = 27011771136. Its totient is φ = 14457600000.

The previous prime is 20109110011. The next prime is 20109110159. The reversal of 20109110021 is 12001190102.

It is a cyclic number.

It is not a de Polignac number, because 20109110021 - 2²⁶ = 20042001157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20109110011) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4002491 + ... + 4007511.

It is an arithmetic number, because the mean of its divisors is an integer number (844117848).

Almost surely, 2^20109110021 is an apocalyptic number.

It is an amenable number.

20109110021 is a deficient number, since it is larger than the sum of its proper divisors (6902661115).

20109110021 is a wasteful number, since it uses less digits than its factorization.

20109110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9053.

The product of its (nonzero) digits is 36, while the sum is 17.

It can be divided in two parts, 201091 and 10021, that added together give a palindrome (211112).

The spelling of 20109110021 in words is "twenty billion, one hundred nine million, one hundred ten thousand, twenty-one".