7800040 has 32 divisors (see below), whose sum is σ = 17721000. Its totient is φ = 3089664.

The previous prime is 7800029. The next prime is 7800041. The reversal of 7800040 is 400087.

7800040 = T₁₅₁ + T₁₅₂ + ... + T₃₆₈.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7739524 + 60516 = 2782^2 + 246^2 .

It is a junction number, because it is equal to n+sod(n) for n = 7799990 and 7800017.

It is not an unprimeable number, because it can be changed into a prime (7800041) 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 7 ways as a sum of consecutive naturals, for example, 3466 + ... + 5254.

Almost surely, 2^7800040 is an apocalyptic number.

It is an amenable number.

7800040 is an abundant number, since it is smaller than the sum of its proper divisors (9920960).

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

7800040 is a wasteful number, since it uses less digits than its factorization.

7800040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1909 (or 1905 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 7800040 is about 2792.8551698933. The cubic root of 7800040 is about 198.3195872748.

The spelling of 7800040 in words is "seven million, eight hundred thousand, forty".