18120954581 has 2 divisors, whose sum is σ = 18120954582. Its totient is φ = 18120954580.

The previous prime is 18120954571. The next prime is 18120954617. The reversal of 18120954581 is 18545902181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13505926225 + 4615028356 = 116215^2 + 67934^2 .

It is a cyclic number.

It is not a de Polignac number, because 18120954581 - 2¹⁸ = 18120692437 is a prime.

It is a super-2 number, since 2×18120954581² (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 (18120954571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9060477290 + 9060477291.

It is an arithmetic number, because the mean of its divisors is an integer number (9060477291).

Almost surely, 2^18120954581 is an apocalyptic number.

It is an amenable number.

18120954581 is a deficient number, since it is larger than the sum of its proper divisors (1).

18120954581 is an equidigital number, since it uses as much as digits as its factorization.

18120954581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 115200, while the sum is 44.

The spelling of 18120954581 in words is "eighteen billion, one hundred twenty million, nine hundred fifty-four thousand, five hundred eighty-one".