7978545 has 12 divisors (see below), whose sum is σ = 13829556. Its totient is φ = 4255200.

The previous prime is 7978519. The next prime is 7978547. The reversal of 7978545 is 5458797.

It can be written as a sum of positive squares in 2 ways, for example, as 2614689 + 5363856 = 1617^2 + 2316^2 .

It is not a de Polignac number, because 7978545 - 2¹⁰ = 7977521 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 177301 = 7978545 / (7 + 9 + 7 + 8 + 5 + 4 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 7978545.

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 11 ways as a sum of consecutive naturals, for example, 88606 + ... + 88695.

It is an arithmetic number, because the mean of its divisors is an integer number (1152463).

Almost surely, 2^7978545 is an apocalyptic number.

It is an amenable number.

7978545 is a deficient number, since it is larger than the sum of its proper divisors (5851011).

7978545 is a wasteful number, since it uses less digits than its factorization.

7978545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177312 (or 177309 counting only the distinct ones).

The product of its digits is 352800, while the sum is 45.

The square root of 7978545 is about 2824.6318344167. The cubic root of 7978545 is about 199.8210482625.

The spelling of 7978545 in words is "seven million, nine hundred seventy-eight thousand, five hundred forty-five".