20257121 has 2 divisors, whose sum is σ = 20257122. Its totient is φ = 20257120.

The previous prime is 20257117. The next prime is 20257163. The reversal of 20257121 is 12175202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17106496 + 3150625 = 4136^2 + 1775^2 .

It is a cyclic number.

It is not a de Polignac number, because 20257121 - 2² = 20257117 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 20257093 and 20257102.

It is not a weakly prime, because it can be changed into another prime (20257621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10128560 + 10128561.

It is an arithmetic number, because the mean of its divisors is an integer number (10128561).

Almost surely, 2^20257121 is an apocalyptic number.

It is an amenable number.

20257121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20257121 is an equidigital number, since it uses as much as digits as its factorization.

20257121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 20257121 is about 4500.7911526753. The cubic root of 20257121 is about 272.6000350959.

The spelling of 20257121 in words is "twenty million, two hundred fifty-seven thousand, one hundred twenty-one".