20121121 has 2 divisors, whose sum is σ = 20121122. Its totient is φ = 20121120.

The previous prime is 20121107. The next prime is 20121137. The reversal of 20121121 is 12112102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11826721 + 8294400 = 3439^2 + 2880^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121121 - 2⁷ = 20120993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20121098 and 20121107.

It is not a weakly prime, because it can be changed into another prime (20121191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10060560 + 10060561.

It is an arithmetic number, because the mean of its divisors is an integer number (10060561).

Almost surely, 2^20121121 is an apocalyptic number.

It is an amenable number.

20121121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20121121 is an equidigital number, since it uses as much as digits as its factorization.

20121121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 20121121 is about 4485.6572539596. The cubic root of 20121121 is about 271.9886141788.

Adding to 20121121 its reverse (12112102), we get a palindrome (32233223).

The spelling of 20121121 in words is "twenty million, one hundred twenty-one thousand, one hundred twenty-one".