19981136448 has 336 divisors, whose sum is σ = 71192599296. Its totient is φ = 5217177600.

The previous prime is 19981136443. The next prime is 19981136453. The reversal of 19981136448 is 84463118991.

19981136448 is a `hidden beast` number, since 1 + 99 + 81 + 1 + 36 + 448 = 666.

It is an interprime number because it is at equal distance from previous prime (19981136443) and next prime (19981136453).

It is a tau number, because it is divible by the number of its divisors (336).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 19981136394 and 19981136403.

It is not an unprimeable number, because it can be changed into a prime (19981136443) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5396998 + ... + 5400698.

It is an arithmetic number, because the mean of its divisors is an integer number (211882736).

Almost surely, 2^19981136448 is an apocalyptic number.

19981136448 is a gapful number since it is divisible by the number (18) 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 19981136448, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35596299648).

19981136448 is an abundant number, since it is smaller than the sum of its proper divisors (51211462848).

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

19981136448 is a wasteful number, since it uses less digits than its factorization.

19981136448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3842 (or 3829 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 54.

The spelling of 19981136448 in words is "nineteen billion, nine hundred eighty-one million, one hundred thirty-six thousand, four hundred forty-eight".