19917697320 has 192 divisors, whose sum is σ = 67850939520. Its totient is φ = 5057597952.

The previous prime is 19917697313. The next prime is 19917697361. The reversal of 19917697320 is 2379671991.

It is a happy number.

It is a super-2 number, since 2×19917697320² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1874262 + ... + 1884858.

It is an arithmetic number, because the mean of its divisors is an integer number (353390310).

Almost surely, 2^19917697320 is an apocalyptic number.

19917697320 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 19917697320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33925469760).

19917697320 is an abundant number, since it is smaller than the sum of its proper divisors (47933242200).

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

19917697320 is a wasteful number, since it uses less digits than its factorization.

19917697320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10864 (or 10857 counting only the distinct ones).

The product of its (nonzero) digits is 1285956, while the sum is 54.

The spelling of 19917697320 in words is "nineteen billion, nine hundred seventeen million, six hundred ninety-seven thousand, three hundred twenty".