1918644348631 has 4 divisors (see below), whose sum is σ = 1920817219672. Its totient is φ = 1916471477592.

The previous prime is 1918644348619. The next prime is 1918644348659. The reversal of 1918644348631 is 1368434468191.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1918644348631 - 2²⁷ = 1918510130903 is a prime.

It is a super-2 number, since 2×1918644348631² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918644349631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1086434196 + ... + 1086435961.

It is an arithmetic number, because the mean of its divisors is an integer number (480204304918).

Almost surely, 2^{1918644348631} is an apocalyptic number.

1918644348631 is a deficient number, since it is larger than the sum of its proper divisors (2172871041).

1918644348631 is an equidigital number, since it uses as much as digits as its factorization.

1918644348631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2172871040.

The product of its digits is 11943936, while the sum is 58.

The spelling of 1918644348631 in words is "one trillion, nine hundred eighteen billion, six hundred forty-four million, three hundred forty-eight thousand, six hundred thirty-one".