655578 has 72 divisors (see below), whose sum is σ = 1825824. Its totient is φ = 166320.

The previous prime is 655561. The next prime is 655579. The reversal of 655578 is 875556.

Its product of digits (42000) is a multiple of the sum of its prime factors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655579) by changing a digit.

655578 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15225 + ... + 15267.

2⁶⁵⁵⁵⁷⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655578, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (912912).

655578 is an abundant number, since it is smaller than the sum of its proper divisors (1170246).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

655578 is a wasteful number, since it uses less digits than its factorization.

655578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80 (or 66 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 655578 is about 809.6777136614. The cubic root of 655578 is about 86.8709938977.

The spelling of 655578 in words is "six hundred fifty-five thousand, five hundred seventy-eight".