7405840 has 40 divisors (see below), whose sum is σ = 18545688. Its totient is φ = 2734080.

The previous prime is 7405831. The next prime is 7405859. The reversal of 7405840 is 485047.

It can be written as a sum of positive squares in 4 ways, for example, as 266256 + 7139584 = 516^2 + 2672^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×7405840² = 109692932211200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 7405799 and 7405808.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2521 + ... + 4600.

Almost surely, 2^7405840 is an apocalyptic number.

It is an amenable number.

7405840 is an abundant number, since it is smaller than the sum of its proper divisors (11139848).

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

7405840 is a wasteful number, since it uses less digits than its factorization.

7405840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7147 (or 7141 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 28.

The square root of 7405840 is about 2721.3673033973. The cubic root of 7405840 is about 194.9207655298.

The spelling of 7405840 in words is "seven million, four hundred five thousand, eight hundred forty".