84178561 has 8 divisors (see below), whose sum is σ = 87189480. Its totient is φ = 81174912.

The previous prime is 84178541. The next prime is 84178573. The reversal of 84178561 is 16587148.

It can be written as a sum of positive squares in 4 ways, for example, as 3538161 + 80640400 = 1881^2 + 8980^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 84178561 - 2¹⁵ = 84145793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (84178541) 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, 33981 + ... + 36373.

It is an arithmetic number, because the mean of its divisors is an integer number (10898685).

Almost surely, 2^84178561 is an apocalyptic number.

It is an amenable number.

84178561 is a deficient number, since it is larger than the sum of its proper divisors (3010919).

84178561 is a wasteful number, since it uses less digits than its factorization.

84178561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3635.

The product of its digits is 53760, while the sum is 40.

The square root of 84178561 is about 9174.8875197465. The cubic root of 84178561 is about 438.2620163128.

The spelling of 84178561 in words is "eighty-four million, one hundred seventy-eight thousand, five hundred sixty-one".