20989242168 has 64 divisors (see below), whose sum is σ = 57352043520. Its totient is φ = 6372441600.

The previous prime is 20989242163. The next prime is 20989242193. The reversal of 20989242168 is 86124298902.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a self number, because there is not a number n which added to its sum of digits gives 20989242168.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20989242163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 817098 + ... + 842393.

It is an arithmetic number, because the mean of its divisors is an integer number (896125680).

Almost surely, 2^20989242168 is an apocalyptic number.

It is an amenable number.

20989242168 is an abundant number, since it is smaller than the sum of its proper divisors (36362801352).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20989242168 is a wasteful number, since it uses less digits than its factorization.

20989242168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659548 (or 1659544 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 51.

The spelling of 20989242168 in words is "twenty billion, nine hundred eighty-nine million, two hundred forty-two thousand, one hundred sixty-eight".