6978555 has 20 divisors (see below), whose sum is σ = 12510432. Its totient is φ = 3721680.

The previous prime is 6978547. The next prime is 6978593. The reversal of 6978555 is 5558796.

6978555 is a `hidden beast` number, since 6 + 97 + 8 + 555 = 666.

It is not a de Polignac number, because 6978555 - 2³ = 6978547 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

6978555 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6978555.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8211 + ... + 9020.

Almost surely, 2^6978555 is an apocalyptic number.

6978555 is a deficient number, since it is larger than the sum of its proper divisors (5531877).

6978555 is a wasteful number, since it uses less digits than its factorization.

6978555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17248 (or 17239 counting only the distinct ones).

The product of its digits is 378000, while the sum is 45.

The square root of 6978555 is about 2641.6954782866. The cubic root of 6978555 is about 191.0975717403.

The spelling of 6978555 in words is "six million, nine hundred seventy-eight thousand, five hundred fifty-five".