7978540 has 24 divisors (see below), whose sum is σ = 16828560. Its totient is φ = 3177408.

The previous prime is 7978519. The next prime is 7978547. The reversal of 7978540 is 458797.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 7978493 and 7978502.

It is not an unprimeable number, because it can be changed into a prime (7978547) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4639 + ... + 6121.

It is an arithmetic number, because the mean of its divisors is an integer number (701190).

Almost surely, 2^7978540 is an apocalyptic number.

It is an amenable number.

7978540 is an abundant number, since it is smaller than the sum of its proper divisors (8850020).

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

7978540 is a wasteful number, since it uses less digits than its factorization.

7978540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1761 (or 1759 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 7978540 is about 2824.6309493454. The cubic root of 7978540 is about 199.8210065211.

The spelling of 7978540 in words is "seven million, nine hundred seventy-eight thousand, five hundred forty".