7840040 has 32 divisors (see below), whose sum is σ = 18998280. Its totient is φ = 2894592.

The previous prime is 7840037. The next prime is 7840057. The reversal of 7840040 is 400487.

It can be written as a sum of positive squares in 4 ways, for example, as 2540836 + 5299204 = 1594^2 + 2302^2 .

It is a super-2 number, since 2×7840040² = 122932454403200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 7839988 and 7840015.

It is an unprimeable number.

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, 7019 + ... + 8058.

Almost surely, 2^7840040 is an apocalyptic number.

It is an amenable number.

7840040 is an abundant number, since it is smaller than the sum of its proper divisors (11158240).

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

7840040 is a wasteful number, since it uses less digits than its factorization.

7840040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15101 (or 15097 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 7840040 is about 2800.0071428480. The cubic root of 7840040 is about 198.6580155285.

The spelling of 7840040 in words is "seven million, eight hundred forty thousand, forty".