917968121856 has 312 divisors, whose sum is σ = 2869418697600. Its totient is φ = 292678189056.

The previous prime is 917968121839. The next prime is 917968121891. The reversal of 917968121856 is 658121869719.

It is a junction number, because it is equal to n+sod(n) for n = 917968121793 and 917968121802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22872495 + ... + 22912593.

It is an arithmetic number, because the mean of its divisors is an integer number (9196854800).

Almost surely, 2^917968121856 is an apocalyptic number.

917968121856 is a gapful number since it is divisible by the number (96) 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 917968121856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1434709348800).

917968121856 is an abundant number, since it is smaller than the sum of its proper divisors (1951450575744).

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

917968121856 is an equidigital number, since it uses as much as digits as its factorization.

917968121856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40161 (or 40127 counting only the distinct ones).

The product of its digits is 13063680, while the sum is 63.

The spelling of 917968121856 in words is "nine hundred seventeen billion, nine hundred sixty-eight million, one hundred twenty-one thousand, eight hundred fifty-six".