7989840 has 140 divisors (see below), whose sum is σ = 28055124. Its totient is φ = 2115072.

The previous prime is 7989769. The next prime is 7989851. The reversal of 7989840 is 489897.

It can be written as a sum of positive squares in 2 ways, for example, as 3779136 + 4210704 = 1944^2 + 2052^2 .

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 58252 + ... + 58388.

Almost surely, 2^7989840 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 7989840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14027562).

7989840 is an abundant number, since it is smaller than the sum of its proper divisors (20065284).

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

7989840 is a wasteful number, since it uses less digits than its factorization.

7989840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 7989840 is about 2826.6305029133. The cubic root of 7989840 is about 199.9152974658.

The spelling of 7989840 in words is "seven million, nine hundred eighty-nine thousand, eight hundred forty".