7899840 has 168 divisors, whose sum is σ = 29401008. Its totient is φ = 1935360.

The previous prime is 7899821. The next prime is 7899851. The reversal of 7899840 is 489987.

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 23 ways as a sum of consecutive naturals, for example, 37335 + ... + 37545.

It is an arithmetic number, because the mean of its divisors is an integer number (175006).

Almost surely, 2^7899840 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 7899840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14700504).

7899840 is an abundant number, since it is smaller than the sum of its proper divisors (21501168).

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

7899840 is a wasteful number, since it uses less digits than its factorization.

7899840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247 (or 234 counting only the distinct ones).

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

The square root of 7899840 is about 2810.6654016442. The cubic root of 7899840 is about 199.1618255584.

The spelling of 7899840 in words is "seven million, eight hundred ninety-nine thousand, eight hundred forty".