18356771837 has 2 divisors, whose sum is σ = 18356771838. Its totient is φ = 18356771836.

The previous prime is 18356771833. The next prime is 18356771933. The reversal of 18356771837 is 73817765381.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10756593796 + 7600178041 = 103714^2 + 87179^2 .

It is a cyclic number.

It is not a de Polignac number, because 18356771837 - 2² = 18356771833 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18356771833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9178385918 + 9178385919.

It is an arithmetic number, because the mean of its divisors is an integer number (9178385919).

Almost surely, 2^18356771837 is an apocalyptic number.

It is an amenable number.

18356771837 is a deficient number, since it is larger than the sum of its proper divisors (1).

18356771837 is an equidigital number, since it uses as much as digits as its factorization.

18356771837 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5927040, while the sum is 56.

The spelling of 18356771837 in words is "eighteen billion, three hundred fifty-six million, seven hundred seventy-one thousand, eight hundred thirty-seven".