20985136117 has 12 divisors (see below), whose sum is σ = 23689725388. Its totient is φ = 18561787200.

The previous prime is 20985136057. The next prime is 20985136127. The reversal of 20985136117 is 71163158902.

It can be written as a sum of positive squares in 2 ways, for example, as 7950575556 + 13034560561 = 89166^2 + 114169^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20985136117 is a prime.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20985136127) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2339184 + ... + 2348137.

Almost surely, 2^20985136117 is an apocalyptic number.

It is an amenable number.

20985136117 is a deficient number, since it is larger than the sum of its proper divisors (2704589271).

20985136117 is a wasteful number, since it uses less digits than its factorization.

20985136117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4687380 (or 4687369 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 43.

The spelling of 20985136117 in words is "twenty billion, nine hundred eighty-five million, one hundred thirty-six thousand, one hundred seventeen".