657985 has 8 divisors (see below), whose sum is σ = 836136. Its totient is φ = 495360.

The previous prime is 657983. The next prime is 658001. The reversal of 657985 is 589756.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 62001 + 595984 = 249^2 + 772^2 .

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

It is not a de Polignac number, because 657985 - 2¹ = 657983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (657983) 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, 3786 + ... + 3955.

It is an arithmetic number, because the mean of its divisors is an integer number (104517).

2⁶⁵⁷⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

657985 is a deficient number, since it is larger than the sum of its proper divisors (178151).

657985 is a wasteful number, since it uses less digits than its factorization.

657985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7763.

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

The square root of 657985 is about 811.1627456929. The cubic root of 657985 is about 86.9771816671.

The spelling of 657985 in words is "six hundred fifty-seven thousand, nine hundred eighty-five".