19961856000 has 720 divisors, whose sum is σ = 77901576480. Its totient is φ = 5042995200.

The previous prime is 19961855993. The next prime is 19961856007. The reversal of 19961856000 is 65816991.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is an interprime number because it is at equal distance from previous prime (19961855993) and next prime (19961856007).

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 (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19961856007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1050623991 + ... + 1050624009.

It is an arithmetic number, because the mean of its divisors is an integer number (108196634).

Almost surely, 2^19961856000 is an apocalyptic number.

19961856000 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 19961856000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38950788240).

19961856000 is an abundant number, since it is smaller than the sum of its proper divisors (57939720480).

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

19961856000 is an frugal number, since it uses more digits than its factorization.

19961856000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 45.

The spelling of 19961856000 in words is "nineteen billion, nine hundred sixty-one million, eight hundred fifty-six thousand".