997800720000 has 2560 divisors, whose sum is σ = 4404989952000. Its totient is φ = 198696960000.

The previous prime is 997800719963. The next prime is 997800720047. The reversal of 997800720000 is 27008799.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

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 319 ways as a sum of consecutive naturals, for example, 32187119985 + ... + 32187120015.

It is an arithmetic number, because the mean of its divisors is an integer number (1720699200).

Almost surely, 2^997800720000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997800720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2202494976000).

997800720000 is an abundant number, since it is smaller than the sum of its proper divisors (3407189232000).

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

997800720000 is a wasteful number, since it uses less digits than its factorization.

997800720000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

Adding to 997800720000 its reverse (27008799), we get a palindrome (997827728799).

The spelling of 997800720000 in words is "nine hundred ninety-seven billion, eight hundred million, seven hundred twenty thousand".