19817868672 has 256 divisors, whose sum is σ = 69754291200. Its totient is φ = 5415911424.

The previous prime is 19817868671. The next prime is 19817868727. The reversal of 19817868672 is 27686871891.

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 not an unprimeable number, because it can be changed into a prime (19817868671) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 538608 + ... + 574224.

It is an arithmetic number, because the mean of its divisors is an integer number (272477700).

Almost surely, 2^19817868672 is an apocalyptic number.

19817868672 is a gapful number since it is divisible by the number (12) 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 19817868672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34877145600).

19817868672 is an abundant number, since it is smaller than the sum of its proper divisors (49936422528).

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

19817868672 is a wasteful number, since it uses less digits than its factorization.

19817868672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35670 (or 35652 counting only the distinct ones).

The product of its digits is 16257024, while the sum is 63.

The spelling of 19817868672 in words is "nineteen billion, eight hundred seventeen million, eight hundred sixty-eight thousand, six hundred seventy-two".