84678561 has 16 divisors (see below), whose sum is σ = 136854720. Its totient is φ = 51320160.

The previous prime is 84678499. The next prime is 84678563. The reversal of 84678561 is 16587648.

It is a happy number.

84678561 is a `hidden beast` number, since 84 + 6 + 7 + 8 + 561 = 666.

It is not a de Polignac number, because 84678561 - 2⁹ = 84678049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (84678563) 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 15 ways as a sum of consecutive naturals, for example, 142260 + ... + 142853.

It is an arithmetic number, because the mean of its divisors is an integer number (8553420).

Almost surely, 2^84678561 is an apocalyptic number.

It is an amenable number.

84678561 is a deficient number, since it is larger than the sum of its proper divisors (52176159).

84678561 is a wasteful number, since it uses less digits than its factorization.

84678561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285133 (or 285127 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 84678561 is about 9202.0954678812. The cubic root of 84678561 is about 439.1280268905.

It can be divided in two parts, 8 and 4678561, that added together give a square (4678569 = 2163²).

The spelling of 84678561 in words is "eighty-four million, six hundred seventy-eight thousand, five hundred sixty-one".