978655 has 4 divisors (see below), whose sum is σ = 1174392. Its totient is φ = 782920.

The previous prime is 978647. The next prime is 978683. The reversal of 978655 is 556879.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 556879 = 157 ⋅3547.

It is not a de Polignac number, because 978655 - 2³ = 978647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 97861 + ... + 97870.

It is an arithmetic number, because the mean of its divisors is an integer number (293598).

2⁹⁷⁸⁶⁵⁵ is an apocalyptic number.

978655 is a deficient number, since it is larger than the sum of its proper divisors (195737).

978655 is a wasteful number, since it uses less digits than its factorization.

978655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195736.

The product of its digits is 75600, while the sum is 40.

The square root of 978655 is about 989.2699328293. The cubic root of 978655 is about 99.2833767790.

The spelling of 978655 in words is "nine hundred seventy-eight thousand, six hundred fifty-five".