20566129 has 2 divisors, whose sum is σ = 20566130. Its totient is φ = 20566128.

The previous prime is 20566123. The next prime is 20566159. The reversal of 20566129 is 92166502.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19847025 + 719104 = 4455^2 + 848^2 .

It is a cyclic number.

It is not a de Polignac number, because 20566129 - 2³ = 20566121 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 20566129.

It is not a weakly prime, because it can be changed into another prime (20566121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10283064 + 10283065.

It is an arithmetic number, because the mean of its divisors is an integer number (10283065).

Almost surely, 2^20566129 is an apocalyptic number.

It is an amenable number.

20566129 is a deficient number, since it is larger than the sum of its proper divisors (1).

20566129 is an equidigital number, since it uses as much as digits as its factorization.

20566129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 20566129 is about 4534.9894156437. The cubic root of 20566129 is about 273.9791528707.

The spelling of 20566129 in words is "twenty million, five hundred sixty-six thousand, one hundred twenty-nine".