7987840 has 64 divisors (see below), whose sum is σ = 21836160. Its totient is φ = 2737152.

The previous prime is 7987823. The next prime is 7987843. The reversal of 7987840 is 487897.

7987840 is nontrivially palindromic in base 15.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (7987843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3589 + ... + 5371.

It is an arithmetic number, because the mean of its divisors is an integer number (341190).

Almost surely, 2^7987840 is an apocalyptic number.

7987840 is a gapful number since it is divisible by the number (70) 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 7987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10918080).

7987840 is an abundant number, since it is smaller than the sum of its proper divisors (13848320).

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

7987840 is a wasteful number, since it uses less digits than its factorization.

7987840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1809 (or 1797 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 43.

The square root of 7987840 is about 2826.2767026602. The cubic root of 7987840 is about 199.8986152810.

The spelling of 7987840 in words is "seven million, nine hundred eighty-seven thousand, eight hundred forty".