18156785293 has 2 divisors, whose sum is σ = 18156785294. Its totient is φ = 18156785292.

The previous prime is 18156785291. The next prime is 18156785329. The reversal of 18156785293 is 39258765181.

Together with next prime (18156785329) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17613802089 + 542983204 = 132717^2 + 23302^2 .

It is a cyclic number.

It is not a de Polignac number, because 18156785293 - 2¹ = 18156785291 is a prime.

It is a super-2 number, since 2×18156785293² (a number of 21 digits) contains 22 as substring.

Together with 18156785291, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18156785291) 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, 9078392646 + 9078392647.

It is an arithmetic number, because the mean of its divisors is an integer number (9078392647).

Almost surely, 2^18156785293 is an apocalyptic number.

It is an amenable number.

18156785293 is a deficient number, since it is larger than the sum of its proper divisors (1).

18156785293 is an equidigital number, since it uses as much as digits as its factorization.

18156785293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3628800, while the sum is 55.

The spelling of 18156785293 in words is "eighteen billion, one hundred fifty-six million, seven hundred eighty-five thousand, two hundred ninety-three".