997884740538 has 192 divisors, whose sum is σ = 2707766634240. Its totient is φ = 270101148480.

The previous prime is 997884740537. The next prime is 997884740543. The reversal of 997884740538 is 835047488799.

997884740538 is a `hidden beast` number, since 9 + 9 + 7 + 8 + 8 + 47 + 40 + 538 = 666.

It is not an unprimeable number, because it can be changed into a prime (997884740537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 11007958 + ... + 11098238.

It is an arithmetic number, because the mean of its divisors is an integer number (14102951220).

Almost surely, 2^997884740538 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997884740538, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1353883317120).

997884740538 is an abundant number, since it is smaller than the sum of its proper divisors (1709881893702).

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

997884740538 is an equidigital number, since it uses as much as digits as its factorization.

997884740538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90349 (or 90312 counting only the distinct ones).

The product of its (nonzero) digits is 487710720, while the sum is 72.

The spelling of 997884740538 in words is "nine hundred ninety-seven billion, eight hundred eighty-four million, seven hundred forty thousand, five hundred thirty-eight".