19805940000 has 720 divisors, whose sum is σ = 87809641920. Its totient is φ = 4112640000.

The previous prime is 19805939983. The next prime is 19805940029. The reversal of 19805940000 is 4950891.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 119 ways as a sum of consecutive naturals, for example, 13859286 + ... + 13860714.

It is an arithmetic number, because the mean of its divisors is an integer number (121957836).

Almost surely, 2^19805940000 is an apocalyptic number.

19805940000 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 19805940000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43904820960).

19805940000 is an abundant number, since it is smaller than the sum of its proper divisors (68003701920).

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

19805940000 is a wasteful number, since it uses less digits than its factorization.

19805940000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1483 (or 1457 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

It can be divided in two parts, 19805 and 940000, that added together give a triangular number (959805 = T₁₃₈₅).

The spelling of 19805940000 in words is "nineteen billion, eight hundred five million, nine hundred forty thousand".