20121021084 has 12 divisors (see below), whose sum is σ = 46949049224. Its totient is φ = 6707007024.

The previous prime is 20121021083. The next prime is 20121021101. The reversal of 20121021084 is 48012012102.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 20121021084.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121021083) 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 3 ways as a sum of consecutive naturals, for example, 838375867 + ... + 838375890.

Almost surely, 2^20121021084 is an apocalyptic number.

It is an amenable number.

20121021084 is an abundant number, since it is smaller than the sum of its proper divisors (26828028140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20121021084 is a wasteful number, since it uses less digits than its factorization.

20121021084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1676751764 (or 1676751762 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 20121021084 its reverse (48012012102), we get a palindrome (68133033186).

The spelling of 20121021084 in words is "twenty billion, one hundred twenty-one million, twenty-one thousand, eighty-four".