1918931508 has 144 divisors (see below), whose sum is σ = 5722451280. Its totient is φ = 536481792.

The previous prime is 1918931507. The next prime is 1918931513. The reversal of 1918931508 is 8051398191.

It can be written as a sum of positive squares in 8 ways, for example, as 158457744 + 1760473764 = 12588^2 + 41958^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1918931507) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 226566 + ... + 234882.

It is an arithmetic number, because the mean of its divisors is an integer number (39739245).

Almost surely, 2^1918931508 is an apocalyptic number.

1918931508 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1918931508, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2861225640).

1918931508 is an abundant number, since it is smaller than the sum of its proper divisors (3803519772).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1918931508 is a wasteful number, since it uses less digits than its factorization.

1918931508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8386 (or 8381 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 45.

The square root of 1918931508 is about 43805.6104625880. The cubic root of 1918931508 is about 1242.6624003578.

The spelling of 1918931508 in words is "one billion, nine hundred eighteen million, nine hundred thirty-one thousand, five hundred eight".