20983765181 has 16 divisors (see below), whose sum is σ = 21897630720. Its totient is φ = 20085461760.

The previous prime is 20983765169. The next prime is 20983765207. The reversal of 20983765181 is 18156738902.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20983765181 is a prime.

It is a super-2 number, since 2×20983765181² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20983765081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1756055 + ... + 1767963.

It is an arithmetic number, because the mean of its divisors is an integer number (1368601920).

Almost surely, 2^20983765181 is an apocalyptic number.

It is an amenable number.

20983765181 is a deficient number, since it is larger than the sum of its proper divisors (913865539).

20983765181 is a wasteful number, since it uses less digits than its factorization.

20983765181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12556.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 20983765181 in words is "twenty billion, nine hundred eighty-three million, seven hundred sixty-five thousand, one hundred eighty-one".