20399031181 has 2 divisors, whose sum is σ = 20399031182. Its totient is φ = 20399031180.

The previous prime is 20399031089. The next prime is 20399031209. The reversal of 20399031181 is 18113099302.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19724798025 + 674233156 = 140445^2 + 25966^2 .

It is a cyclic number.

It is not a de Polignac number, because 20399031181 - 2⁹ = 20399030669 is a prime.

It is a super-2 number, since 2×20399031181² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20399031181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20399031481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10199515590 + 10199515591.

It is an arithmetic number, because the mean of its divisors is an integer number (10199515591).

Almost surely, 2^20399031181 is an apocalyptic number.

It is an amenable number.

20399031181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20399031181 is an equidigital number, since it uses as much as digits as its factorization.

20399031181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 37.

The spelling of 20399031181 in words is "twenty billion, three hundred ninety-nine million, thirty-one thousand, one hundred eighty-one".