3978565668 has 576 divisors, whose sum is σ = 14185758720. Its totient is φ = 940896000.

The previous prime is 3978565589. The next prime is 3978565697. The reversal of 3978565668 is 8665658793.

3978565668 is a `hidden beast` number, since 3 + 9 + 7 + 8 + 565 + 6 + 68 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 65222358 + ... + 65222418.

Almost surely, 2^3978565668 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 3978565668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7092879360).

3978565668 is an abundant number, since it is smaller than the sum of its proper divisors (10207193052).

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

3978565668 is a wasteful number, since it uses less digits than its factorization.

3978565668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 157 (or 138 counting only the distinct ones).

The product of its digits is 65318400, while the sum is 63.

The square root of 3978565668 is about 63075.8723126363. The cubic root of 3978565668 is about 1584.5605654856.

The spelling of 3978565668 in words is "three billion, nine hundred seventy-eight million, five hundred sixty-five thousand, six hundred sixty-eight".