20872685129 has 4 divisors (see below), whose sum is σ = 21000738576. Its totient is φ = 20744631684.

The previous prime is 20872685063. The next prime is 20872685159. The reversal of 20872685129 is 92158627802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20872685129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20872685159) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64026479 + ... + 64026804.

It is an arithmetic number, because the mean of its divisors is an integer number (5250184644).

Almost surely, 2^20872685129 is an apocalyptic number.

It is an amenable number.

20872685129 is a deficient number, since it is larger than the sum of its proper divisors (128053447).

20872685129 is a wasteful number, since it uses less digits than its factorization.

20872685129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128053446.

The product of its (nonzero) digits is 967680, while the sum is 50.

The spelling of 20872685129 in words is "twenty billion, eight hundred seventy-two million, six hundred eighty-five thousand, one hundred twenty-nine".