997872756353781 has 96 divisors (see below), whose sum is σ = 1725774781409280. Its totient is φ = 507030430233600.

The previous prime is 997872756353771. The next prime is 997872756353801. The reversal of 997872756353781 is 187353657278799.

It is not a de Polignac number, because 997872756353781 - 2¹⁰ = 997872756352757 is a prime.

It is a super-2 number, since 2×997872756353781² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997872756353771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 22834140 + ... + 50171141.

It is an arithmetic number, because the mean of its divisors is an integer number (17976820639680).

Almost surely, 2^{997872756353781} is an apocalyptic number.

It is an amenable number.

997872756353781 is a deficient number, since it is larger than the sum of its proper divisors (727902025055499).

997872756353781 is a wasteful number, since it uses less digits than its factorization.

997872756353781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73005495 (or 73005488 counting only the distinct ones).

The product of its digits is 33606316800, while the sum is 87.

The spelling of 997872756353781 in words is "nine hundred ninety-seven trillion, eight hundred seventy-two billion, seven hundred fifty-six million, three hundred fifty-three thousand, seven hundred eighty-one".