20100021202121 has 6 divisors (see below), whose sum is σ = 23381657316810. Its totient is φ = 17228589601776.

The previous prime is 20100021202111. The next prime is 20100021202133. The reversal of 20100021202121 is 12120212000102.

It can be written as a sum of positive squares in only one way, i.e., 18542669454400 + 1557351747721 = 4306120^2 + 1247939^2 .

It is not a de Polignac number, because 20100021202121 - 2²² = 20100017007817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20100021202096 and 20100021202105.

It is not an unprimeable number, because it can be changed into a prime (20100021202111) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 205102257116 + ... + 205102257213.

It is an arithmetic number, because the mean of its divisors is an integer number (3896942886135).

Almost surely, 2^{20100021202121} is an apocalyptic number.

It is an amenable number.

20100021202121 is a deficient number, since it is larger than the sum of its proper divisors (3281636114689).

20100021202121 is an equidigital number, since it uses as much as digits as its factorization.

20100021202121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410204514343 (or 410204514336 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20100021202121 its reverse (12120212000102), we get a palindrome (32220233202223).

It can be divided in two parts, 2010002 and 1202121, that added together give a palindrome (3212123).

The spelling of 20100021202121 in words is "twenty trillion, one hundred billion, twenty-one million, two hundred two thousand, one hundred twenty-one".