19999810440 has 160 divisors (see below), whose sum is σ = 67561560000. Its totient is φ = 5306311296.

The previous prime is 19999810433. The next prime is 19999810547. The reversal of 19999810440 is 4401899991.

19999810440 is a `hidden beast` number, since 19 + 99 + 98 + 10 + 440 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

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 39 ways as a sum of consecutive naturals, for example, 629251 + ... + 660269.

It is an arithmetic number, because the mean of its divisors is an integer number (422259750).

Almost surely, 2^19999810440 is an apocalyptic number.

19999810440 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 19999810440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33780780000).

19999810440 is an abundant number, since it is smaller than the sum of its proper divisors (47561749560).

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

19999810440 is a wasteful number, since it uses less digits than its factorization.

19999810440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31241 (or 31228 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 54.

The spelling of 19999810440 in words is "nineteen billion, nine hundred ninety-nine million, eight hundred ten thousand, four hundred forty".