20431102121 has 2 divisors, whose sum is σ = 20431102122. Its totient is φ = 20431102120.

The previous prime is 20431102117. The next prime is 20431102171. The reversal of 20431102121 is 12120113402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18867769600 + 1563332521 = 137360^2 + 39539^2 .

It is a cyclic number.

It is not a de Polignac number, because 20431102121 - 2² = 20431102117 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20431102121.

It is not a weakly prime, because it can be changed into another prime (20431102171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215551060 + 10215551061.

It is an arithmetic number, because the mean of its divisors is an integer number (10215551061).

Almost surely, 2^20431102121 is an apocalyptic number.

It is an amenable number.

20431102121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20431102121 is an equidigital number, since it uses as much as digits as its factorization.

20431102121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 20431102121 its reverse (12120113402), we get a palindrome (32551215523).

The spelling of 20431102121 in words is "twenty billion, four hundred thirty-one million, one hundred two thousand, one hundred twenty-one".