18081774437 has 2 divisors, whose sum is σ = 18081774438. Its totient is φ = 18081774436.

The previous prime is 18081774433. The next prime is 18081774497. The reversal of 18081774437 is 73447718081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12754088356 + 5327686081 = 112934^2 + 72991^2 .

It is a cyclic number.

It is not a de Polignac number, because 18081774437 - 2² = 18081774433 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18081774433) 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, 9040887218 + 9040887219.

It is an arithmetic number, because the mean of its divisors is an integer number (9040887219).

Almost surely, 2^18081774437 is an apocalyptic number.

It is an amenable number.

18081774437 is a deficient number, since it is larger than the sum of its proper divisors (1).

18081774437 is an equidigital number, since it uses as much as digits as its factorization.

18081774437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1053696, while the sum is 50.

The spelling of 18081774437 in words is "eighteen billion, eighty-one million, seven hundred seventy-four thousand, four hundred thirty-seven".