3978556920 has 512 divisors, whose sum is σ = 15386112000. Its totient is φ = 905748480.

The previous prime is 3978556913. The next prime is 3978556921. The reversal of 3978556920 is 296558793.

3978556920 is a `hidden beast` number, since 3 + 9 + 78 + 5 + 569 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978556921) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 18855615 + ... + 18855825.

It is an arithmetic number, because the mean of its divisors is an integer number (30051000).

Almost surely, 2^3978556920 is an apocalyptic number.

3978556920 is a gapful number since it is divisible by the number (30) 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 3978556920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7693056000).

3978556920 is an abundant number, since it is smaller than the sum of its proper divisors (11407555080).

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

3978556920 is a wasteful number, since it uses less digits than its factorization.

3978556920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340 (or 330 counting only the distinct ones).

The product of its (nonzero) digits is 4082400, while the sum is 54.

The square root of 3978556920 is about 63075.8029675406. The cubic root of 3978556920 is about 1584.5594041169.

The spelling of 3978556920 in words is "three billion, nine hundred seventy-eight million, five hundred fifty-six thousand, nine hundred twenty".