18420313381 has 2 divisors, whose sum is σ = 18420313382. Its totient is φ = 18420313380.

The previous prime is 18420313337. The next prime is 18420313391. The reversal of 18420313381 is 18331302481.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10776308481 + 7644004900 = 103809^2 + 87430^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18420313381 is a prime.

It is a super-2 number, since 2×18420313381² (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 (18420313391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9210156690 + 9210156691.

It is an arithmetic number, because the mean of its divisors is an integer number (9210156691).

Almost surely, 2^18420313381 is an apocalyptic number.

It is an amenable number.

18420313381 is a deficient number, since it is larger than the sum of its proper divisors (1).

18420313381 is an equidigital number, since it uses as much as digits as its factorization.

18420313381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13824, while the sum is 34.

The spelling of 18420313381 in words is "eighteen billion, four hundred twenty million, three hundred thirteen thousand, three hundred eighty-one".