997958775520 has 192 divisors, whose sum is σ = 2857963046400. Its totient is φ = 321673697280.

The previous prime is 997958775509. The next prime is 997958775551. The reversal of 997958775520 is 25577859799.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2608686 + ... + 2966674.

It is an arithmetic number, because the mean of its divisors is an integer number (14885224200).

Almost surely, 2^997958775520 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 997958775520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1428981523200).

997958775520 is an abundant number, since it is smaller than the sum of its proper divisors (1860004270880).

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

997958775520 is a wasteful number, since it uses less digits than its factorization.

997958775520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358161 (or 358153 counting only the distinct ones).

The product of its (nonzero) digits is 500094000, while the sum is 73.

The spelling of 997958775520 in words is "nine hundred ninety-seven billion, nine hundred fifty-eight million, seven hundred seventy-five thousand, five hundred twenty".