20129897 has 2 divisors, whose sum is σ = 20129898. Its totient is φ = 20129896.

The previous prime is 20129869. The next prime is 20129909. The reversal of 20129897 is 79892102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16516096 + 3613801 = 4064^2 + 1901^2 .

It is a cyclic number.

It is not a de Polignac number, because 20129897 - 2⁶ = 20129833 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20129897.

It is not a weakly prime, because it can be changed into another prime (20129497) 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, 10064948 + 10064949.

It is an arithmetic number, because the mean of its divisors is an integer number (10064949).

Almost surely, 2^20129897 is an apocalyptic number.

It is an amenable number.

20129897 is a deficient number, since it is larger than the sum of its proper divisors (1).

20129897 is an equidigital number, since it uses as much as digits as its factorization.

20129897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 20129897 is about 4486.6353763149. The cubic root of 20129897 is about 272.0281518224.

The spelling of 20129897 in words is "twenty million, one hundred twenty-nine thousand, eight hundred ninety-seven".