971921808 has 160 divisors (see below), whose sum is σ = 3277706880. Its totient is φ = 271848960.

The previous prime is 971921749. The next prime is 971921857. The reversal of 971921808 is 808129179.

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, 53910 + ... + 69642.

It is an arithmetic number, because the mean of its divisors is an integer number (20485668).

Almost surely, 2^971921808 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 971921808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1638853440).

971921808 is an abundant number, since it is smaller than the sum of its proper divisors (2305785072).

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

971921808 is a wasteful number, since it uses less digits than its factorization.

971921808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15774 (or 15762 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 45.

The square root of 971921808 is about 31175.6605062347. The cubic root of 971921808 is about 990.5516117858.

The spelling of 971921808 in words is "nine hundred seventy-one million, nine hundred twenty-one thousand, eight hundred eight".