20129129 has 2 divisors, whose sum is σ = 20129130. Its totient is φ = 20129128.

The previous prime is 20129111. The next prime is 20129141. The reversal of 20129129 is 92192102.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19360000 + 769129 = 4400^2 + 877^2 .

It is a cyclic number.

It is not a de Polignac number, because 20129129 - 2¹² = 20125033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20129098 and 20129107.

It is not a weakly prime, because it can be changed into another prime (20129159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10064564 + 10064565.

It is an arithmetic number, because the mean of its divisors is an integer number (10064565).

Almost surely, 2^20129129 is an apocalyptic number.

It is an amenable number.

20129129 is a deficient number, since it is larger than the sum of its proper divisors (1).

20129129 is an equidigital number, since it uses as much as digits as its factorization.

20129129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 20129129 is about 4486.5497879774. The cubic root of 20129129 is about 272.0246922869.

The spelling of 20129129 in words is "twenty million, one hundred twenty-nine thousand, one hundred twenty-nine".