1918631329 has 12 divisors (see below), whose sum is σ = 1991889900. Its totient is φ = 1847982080.

The previous prime is 1918631327. The next prime is 1918631347. The reversal of 1918631329 is 9231368191.

It can be written as a sum of positive squares in 6 ways, for example, as 28729600 + 1889901729 = 5360^2 + 43473^2 .

It is not a de Polignac number, because 1918631329 - 2¹ = 1918631327 is a prime.

It is a super-2 number, since 2×1918631329² = 7362292353240612482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1918631327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 375069 + ... + 380149.

It is an arithmetic number, because the mean of its divisors is an integer number (165990825).

Almost surely, 2^1918631329 is an apocalyptic number.

It is an amenable number.

1918631329 is a deficient number, since it is larger than the sum of its proper divisors (73258571).

1918631329 is an equidigital number, since it uses as much as digits as its factorization.

1918631329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5588 (or 5559 counting only the distinct ones).

The product of its digits is 69984, while the sum is 43.

The square root of 1918631329 is about 43802.1840665508. The cubic root of 1918631329 is about 1242.5976003015.

The spelling of 1918631329 in words is "one billion, nine hundred eighteen million, six hundred thirty-one thousand, three hundred twenty-nine".