509657 has 4 divisors (see below), whose sum is σ = 531840. Its totient is φ = 487476.

The previous prime is 509653. The next prime is 509659. The reversal of 509657 is 756905.

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, and also an emirpimes, since its reverse is a distinct semiprime: 756905 = 5 ⋅151381.

It is a cyclic number.

It is not a de Polignac number, because 509657 - 2² = 509653 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 (509653) 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, 11057 + ... + 11102.

It is an arithmetic number, because the mean of its divisors is an integer number (132960).

2⁵⁰⁹⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

509657 is a deficient number, since it is larger than the sum of its proper divisors (22183).

509657 is a wasteful number, since it uses less digits than its factorization.

509657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22182.

The product of its (nonzero) digits is 9450, while the sum is 32.

The square root of 509657 is about 713.9026544285. The cubic root of 509657 is about 79.8777821300.

The spelling of 509657 in words is "five hundred nine thousand, six hundred fifty-seven".