7978240 has 72 divisors (see below), whose sum is σ = 20014848. Its totient is φ = 3041280.

The previous prime is 7978237. The next prime is 7978247. The reversal of 7978240 is 428797.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 7978240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7978247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29305 + ... + 29575.

It is an arithmetic number, because the mean of its divisors is an integer number (277984).

Almost surely, 2^7978240 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 7978240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10007424).

7978240 is an abundant number, since it is smaller than the sum of its proper divisors (12036608).

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

7978240 is a wasteful number, since it uses less digits than its factorization.

7978240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315 (or 301 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 7978240 is about 2824.5778445637. The cubic root of 7978240 is about 199.8185020089.

The spelling of 7978240 in words is "seven million, nine hundred seventy-eight thousand, two hundred forty".