1918373738209 has 2 divisors, whose sum is σ = 1918373738210. Its totient is φ = 1918373738208.

The previous prime is 1918373738189. The next prime is 1918373738213. The reversal of 1918373738209 is 9028373738191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1631822295184 + 286551443025 = 1277428^2 + 535305^2 .

It is a cyclic number.

It is not a de Polignac number, because 1918373738209 - 2²⁷ = 1918239520481 is a prime.

It is not a weakly prime, because it can be changed into another prime (1918373738509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959186869104 + 959186869105.

It is an arithmetic number, because the mean of its divisors is an integer number (959186869105).

Almost surely, 2^{1918373738209} is an apocalyptic number.

It is an amenable number.

1918373738209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1918373738209 is an equidigital number, since it uses as much as digits as its factorization.

1918373738209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13716864, while the sum is 61.

The spelling of 1918373738209 in words is "one trillion, nine hundred eighteen billion, three hundred seventy-three million, seven hundred thirty-eight thousand, two hundred nine".