20408129 has 8 divisors (see below), whose sum is σ = 23351808. Its totient is φ = 17471520.

The previous prime is 20408117. The next prime is 20408189. The reversal of 20408129 is 92180402.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20408129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20408098 and 20408107.

It is not an unprimeable number, because it can be changed into a prime (20408189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8144 + ... + 10350.

It is an arithmetic number, because the mean of its divisors is an integer number (2918976).

Almost surely, 2^20408129 is an apocalyptic number.

It is an amenable number.

20408129 is a deficient number, since it is larger than the sum of its proper divisors (2943679).

20408129 is a wasteful number, since it uses less digits than its factorization.

20408129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3535.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 20408129 is about 4517.5357220502. The cubic root of 20408129 is about 273.2757303097.

The spelling of 20408129 in words is "twenty million, four hundred eight thousand, one hundred twenty-nine".