3978253440 has 640 divisors, whose sum is σ = 17120822400. Its totient is φ = 859963392.

The previous prime is 3978253361. The next prime is 3978253451. The reversal of 3978253440 is 443528793.

3978253440 is a `hidden beast` number, since 3 + 9 + 78 + 2 + 534 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 6894432 + ... + 6895008.

It is an arithmetic number, because the mean of its divisors is an integer number (26751285).

Almost surely, 2^3978253440 is an apocalyptic number.

3978253440 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 3978253440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8560411200).

3978253440 is an abundant number, since it is smaller than the sum of its proper divisors (13142568960).

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

3978253440 is a wasteful number, since it uses less digits than its factorization.

3978253440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 634 (or 613 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The square root of 3978253440 is about 63073.3972447973. The cubic root of 3978253440 is about 1584.5191136024.

The spelling of 3978253440 in words is "three billion, nine hundred seventy-eight million, two hundred fifty-three thousand, four hundred forty".