20121321012 has 96 divisors (see below), whose sum is σ = 52962674688. Its totient is φ = 5899200384.

The previous prime is 20121320983. The next prime is 20121321013. The reversal of 20121321012 is 21012312102.

It is a junction number, because it is equal to n+sod(n) for n = 20121320982 and 20121321000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121321013) 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, 932983 + ... + 954305.

It is an arithmetic number, because the mean of its divisors is an integer number (551694528).

Almost surely, 2^20121321012 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20121321012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26481337344).

20121321012 is an abundant number, since it is smaller than the sum of its proper divisors (32841353676).

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

20121321012 is a wasteful number, since it uses less digits than its factorization.

20121321012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21629 (or 21627 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 20121321012 its reverse (21012312102), we get a palindrome (41133633114).

The spelling of 20121321012 in words is "twenty billion, one hundred twenty-one million, three hundred twenty-one thousand, twelve".