655993 has 4 divisors (see below), whose sum is σ = 706468. Its totient is φ = 605520.

The previous prime is 655987. The next prime is 656023. The reversal of 655993 is 399556.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 310249 + 345744 = 557^2 + 588^2 .

It is a cyclic number.

It is not a de Polignac number, because 655993 - 2⁵ = 655961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (655913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25218 + ... + 25243.

It is an arithmetic number, because the mean of its divisors is an integer number (176617).

2⁶⁵⁵⁹⁹³ is an apocalyptic number.

It is an amenable number.

655993 is a deficient number, since it is larger than the sum of its proper divisors (50475).

655993 is a wasteful number, since it uses less digits than its factorization.

655993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50474.

The product of its digits is 36450, while the sum is 37.

The square root of 655993 is about 809.9339479242. The cubic root of 655993 is about 86.8893206556.

The spelling of 655993 in words is "six hundred fifty-five thousand, nine hundred ninety-three".