20505342129 has 8 divisors (see below), whose sum is σ = 27341277792. Its totient is φ = 13669817280.

The previous prime is 20505342079. The next prime is 20505342131. The reversal of 20505342129 is 92124350502.

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

It is not a de Polignac number, because 20505342129 - 2⁷ = 20505342001 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20505342129.

It is not an unprimeable number, because it can be changed into a prime (20505342029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43497 + ... + 207129.

It is an arithmetic number, because the mean of its divisors is an integer number (3417659724).

Almost surely, 2^20505342129 is an apocalyptic number.

It is an amenable number.

20505342129 is a deficient number, since it is larger than the sum of its proper divisors (6835935663).

20505342129 is a wasteful number, since it uses less digits than its factorization.

20505342129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205407.

The product of its (nonzero) digits is 21600, while the sum is 33.

The spelling of 20505342129 in words is "twenty billion, five hundred five million, three hundred forty-two thousand, one hundred twenty-nine".