657997 has 4 divisors (see below), whose sum is σ = 659680. Its totient is φ = 656316.

The previous prime is 657983. The next prime is 658001. The reversal of 657997 is 799756.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 657997 - 2¹⁹ = 133709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (657947) 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, 88 + ... + 1150.

It is an arithmetic number, because the mean of its divisors is an integer number (164920).

2⁶⁵⁷⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

657997 is a deficient number, since it is larger than the sum of its proper divisors (1683).

657997 is a wasteful number, since it uses less digits than its factorization.

657997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1682.

The product of its digits is 119070, while the sum is 43.

The square root of 657997 is about 811.1701424485. The cubic root of 657997 is about 86.9777104126.

The spelling of 657997 in words is "six hundred fifty-seven thousand, nine hundred ninety-seven".