7928840 has 16 divisors (see below), whose sum is σ = 17839980. Its totient is φ = 3171520.

The previous prime is 7928831. The next prime is 7928849. The reversal of 7928840 is 488297.

It is an interprime number because it is at equal distance from previous prime (7928831) and next prime (7928849).

It can be written as a sum of positive squares in 2 ways, for example, as 7279204 + 649636 = 2698^2 + 806^2 .

It is a d-powerful number, because it can be written as 7 + 9⁷ + 2⁷ + 8 + 8⁷ + 4¹⁰ + 0 .

It is a junction number, because it is equal to n+sod(n) for n = 7928794 and 7928803.

It is not an unprimeable number, because it can be changed into a prime (7928849) 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 3 ways as a sum of consecutive naturals, for example, 99071 + ... + 99150.

Almost surely, 2^7928840 is an apocalyptic number.

It is an amenable number.

7928840 is an abundant number, since it is smaller than the sum of its proper divisors (9911140).

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

7928840 is a wasteful number, since it uses less digits than its factorization.

7928840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198232 (or 198228 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 7928840 is about 2815.8195964941. The cubic root of 7928840 is about 199.4052330145.

The spelling of 7928840 in words is "seven million, nine hundred twenty-eight thousand, eight hundred forty".