19971796320 has 288 divisors, whose sum is σ = 81314604000. Its totient is φ = 4564933632.

The previous prime is 19971796319. The next prime is 19971796321. The reversal of 19971796320 is 2369717991.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (19971796319) and next prime (19971796321).

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19971796321) 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, 164506 + ... + 258854.

It is an arithmetic number, because the mean of its divisors is an integer number (282342375).

Almost surely, 2^19971796320 is an apocalyptic number.

19971796320 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 19971796320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40657302000).

19971796320 is an abundant number, since it is smaller than the sum of its proper divisors (61342807680).

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

19971796320 is a wasteful number, since it uses less digits than its factorization.

19971796320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94387 (or 94366 counting only the distinct ones).

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

The spelling of 19971796320 in words is "nineteen billion, nine hundred seventy-one million, seven hundred ninety-six thousand, three hundred twenty".