1918187393 has 2 divisors, whose sum is σ = 1918187394. Its totient is φ = 1918187392.

The previous prime is 1918187357. The next prime is 1918187413. The reversal of 1918187393 is 3937818191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1613789584 + 304397809 = 40172^2 + 17447^2 .

It is a cyclic number.

It is not a de Polignac number, because 1918187393 - 2⁶ = 1918187329 is a prime.

It is a super-3 number, since 3×1918187393³ (a number of 29 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1918180393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959093696 + 959093697.

It is an arithmetic number, because the mean of its divisors is an integer number (959093697).

Almost surely, 2^1918187393 is an apocalyptic number.

It is an amenable number.

1918187393 is a deficient number, since it is larger than the sum of its proper divisors (1).

1918187393 is an equidigital number, since it uses as much as digits as its factorization.

1918187393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 50.

The square root of 1918187393 is about 43797.1162635167. The cubic root of 1918187393 is about 1242.5017548324.

The spelling of 1918187393 in words is "one billion, nine hundred eighteen million, one hundred eighty-seven thousand, three hundred ninety-three".