20810129 has 2 divisors, whose sum is σ = 20810130. Its totient is φ = 20810128.

The previous prime is 20810123. The next prime is 20810177. The reversal of 20810129 is 92101802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19492225 + 1317904 = 4415^2 + 1148^2 .

It is a cyclic number.

It is not a de Polignac number, because 20810129 - 2²⁴ = 4032913 is a prime.

It is a super-2 number, since 2×20810129² = 866122937993282, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20810123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10405064 + 10405065.

It is an arithmetic number, because the mean of its divisors is an integer number (10405065).

Almost surely, 2^20810129 is an apocalyptic number.

It is an amenable number.

20810129 is a deficient number, since it is larger than the sum of its proper divisors (1).

20810129 is an equidigital number, since it uses as much as digits as its factorization.

20810129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 20810129 is about 4561.8120303230. The cubic root of 20810129 is about 275.0584074286.

The spelling of 20810129 in words is "twenty million, eight hundred ten thousand, one hundred twenty-nine".