20955747181 has 2 divisors, whose sum is σ = 20955747182. Its totient is φ = 20955747180.

The previous prime is 20955747173. The next prime is 20955747191. The reversal of 20955747181 is 18174755902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15533633956 + 5422113225 = 124634^2 + 73635^2 .

It is a cyclic number.

It is not a de Polignac number, because 20955747181 - 2³ = 20955747173 is a prime.

It is a super-2 number, since 2×20955747181² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20955747191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10477873590 + 10477873591.

It is an arithmetic number, because the mean of its divisors is an integer number (10477873591).

Almost surely, 2^20955747181 is an apocalyptic number.

It is an amenable number.

20955747181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20955747181 is an equidigital number, since it uses as much as digits as its factorization.

20955747181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 705600, while the sum is 49.

The spelling of 20955747181 in words is "twenty billion, nine hundred fifty-five million, seven hundred forty-seven thousand, one hundred eighty-one".