3971657872 has 80 divisors (see below), whose sum is σ = 9496114432. Its totient is φ = 1567019520.

The previous prime is 3971657867. The next prime is 3971657881. The reversal of 3971657872 is 2787561793.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 574597 + ... + 581467.

Almost surely, 2^3971657872 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 3971657872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4748057216).

3971657872 is an abundant number, since it is smaller than the sum of its proper divisors (5524456560).

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

3971657872 is a wasteful number, since it uses less digits than its factorization.

3971657872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7296 (or 7290 counting only the distinct ones).

The product of its digits is 4445280, while the sum is 55.

The square root of 3971657872 is about 63021.0906919263. The cubic root of 3971657872 is about 1583.6429682851.

The spelling of 3971657872 in words is "three billion, nine hundred seventy-one million, six hundred fifty-seven thousand, eight hundred seventy-two".