1918659840 has 144 divisors (see below), whose sum is σ = 6228934656. Its totient is φ = 503193600.

The previous prime is 1918659817. The next prime is 1918659859. The reversal of 1918659840 is 489568191.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 230145 + ... + 238335.

Almost surely, 2^1918659840 is an apocalyptic number.

1918659840 is a gapful number since it is divisible by the number (10) 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 1918659840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3114467328).

1918659840 is an abundant number, since it is smaller than the sum of its proper divisors (4310274816).

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

1918659840 is an equidigital number, since it uses as much as digits as its factorization.

1918659840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8276 (or 8262 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 51.

The square root of 1918659840 is about 43802.5095171498. The cubic root of 1918659840 is about 1242.6037553011.

The spelling of 1918659840 in words is "one billion, nine hundred eighteen million, six hundred fifty-nine thousand, eight hundred forty".