20971667989 has 8 divisors (see below), whose sum is σ = 21767782400. Its totient is φ = 20183029200.

The previous prime is 20971667921. The next prime is 20971667999. The reversal of 20971667989 is 98976617902.

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-20971667989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20971667989.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20971667999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1863189 + ... + 1874410.

It is an arithmetic number, because the mean of its divisors is an integer number (2720972800).

Almost surely, 2^20971667989 is an apocalyptic number.

It is an amenable number.

20971667989 is a deficient number, since it is larger than the sum of its proper divisors (796114411).

20971667989 is a wasteful number, since it uses less digits than its factorization.

20971667989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3737811.

The product of its (nonzero) digits is 20575296, while the sum is 64.

The spelling of 20971667989 in words is "twenty billion, nine hundred seventy-one million, six hundred sixty-seven thousand, nine hundred eighty-nine".