19891726848 has 640 divisors, whose sum is σ = 73328640000. Its totient is φ = 5195612160.

The previous prime is 19891726837. The next prime is 19891726873. The reversal of 19891726848 is 84862719891.

It is a Harshad number since it is a multiple of its sum of digits (63).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 56996178 + ... + 56996526.

It is an arithmetic number, because the mean of its divisors is an integer number (114576000).

Almost surely, 2^19891726848 is an apocalyptic number.

19891726848 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 19891726848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36664320000).

19891726848 is an abundant number, since it is smaller than the sum of its proper divisors (53436913152).

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

19891726848 is a wasteful number, since it uses less digits than its factorization.

19891726848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 411 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 63.

The spelling of 19891726848 in words is "nineteen billion, eight hundred ninety-one million, seven hundred twenty-six thousand, eight hundred forty-eight".