1918131493 has 2 divisors, whose sum is σ = 1918131494. Its totient is φ = 1918131492.

The previous prime is 1918131469. The next prime is 1918131511. The reversal of 1918131493 is 3941318191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1689456609 + 228674884 = 41103^2 + 15122^2 .

It is a cyclic number.

It is not a de Polignac number, because 1918131493 - 2¹³ = 1918123301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1918131893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959065746 + 959065747.

It is an arithmetic number, because the mean of its divisors is an integer number (959065747).

Almost surely, 2^1918131493 is an apocalyptic number.

It is an amenable number.

1918131493 is a deficient number, since it is larger than the sum of its proper divisors (1).

1918131493 is an equidigital number, since it uses as much as digits as its factorization.

1918131493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 40.

The square root of 1918131493 is about 43796.4780889971. The cubic root of 1918131493 is about 1242.4896850136.

The spelling of 1918131493 in words is "one billion, nine hundred eighteen million, one hundred thirty-one thousand, four hundred ninety-three".