1999991040 has 288 divisors, whose sum is σ = 6739117056. Its totient is φ = 504791040.

The previous prime is 1999991011. The next prime is 1999991051. The reversal of 1999991040 is 401999991.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6308962 + ... + 6309278.

It is an arithmetic number, because the mean of its divisors is an integer number (23399712).

Almost surely, 2^1999991040 is an apocalyptic number.

1999991040 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 1999991040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3369558528).

1999991040 is an abundant number, since it is smaller than the sum of its proper divisors (4739126016).

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

1999991040 is a wasteful number, since it uses less digits than its factorization.

1999991040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 236196, while the sum is 51.

The square root of 1999991040 is about 44721.2593740382. The cubic root of 1999991040 is about 1259.9191684100.

The spelling of 1999991040 in words is "one billion, nine hundred ninety-nine million, nine hundred ninety-one thousand, forty".