19821720925440 has 3456 divisors, whose sum is σ = 89648435036160. Its totient is φ = 3939922280448.

The previous prime is 19821720925427. The next prime is 19821720925441. The reversal of 19821720925440 is 4452902712891.

19821720925440 is a `hidden beast` number, since 1 + 9 + 8 + 2 + 1 + 7 + 2 + 0 + 92 + 544 + 0 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19821720925441) by changing a digit.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 156076542657 + ... + 156076542783.

Almost surely, 2^{19821720925440} is an apocalyptic number.

19821720925440 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 19821720925440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44824217518080).

19821720925440 is an abundant number, since it is smaller than the sum of its proper divisors (69826714110720).

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

19821720925440 is a wasteful number, since it uses less digits than its factorization.

19821720925440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 19821720925440 in words is "nineteen trillion, eight hundred twenty-one billion, seven hundred twenty million, nine hundred twenty-five thousand, four hundred forty".