19921889917440 has 1120 divisors, whose sum is σ = 84488801227776. Its totient is φ = 4406595747840.

The previous prime is 19921889917393. The next prime is 19921889917459. The reversal of 19921889917440 is 4471998812991.

19921889917440 is a `hidden beast` number, since 1 + 9 + 9 + 2 + 1 + 88 + 99 + 17 + 440 = 666.

It is a tau number, because it is divible by the number of its divisors (1120).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 404949484 + ... + 404998676.

Almost surely, 2^{19921889917440} is an apocalyptic number.

19921889917440 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 19921889917440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42244400613888).

19921889917440 is an abundant number, since it is smaller than the sum of its proper divisors (64566911310336).

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

19921889917440 is an frugal number, since it uses more digits than its factorization.

19921889917440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49272 (or 49241 counting only the distinct ones).

The product of its (nonzero) digits is 94058496, while the sum is 72.

The spelling of 19921889917440 in words is "nineteen trillion, nine hundred twenty-one billion, eight hundred eighty-nine million, nine hundred seventeen thousand, four hundred forty".