656916509 has 8 divisors (see below), whose sum is σ = 672779520. Its totient is φ = 641132176.

The previous prime is 656916479. The next prime is 656916523. The reversal of 656916509 is 905619656.

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

It is a cyclic number.

It is not a de Polignac number, because 656916509 - 2²⁸ = 388481053 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656916529) 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, 2594 + ... + 36339.

It is an arithmetic number, because the mean of its divisors is an integer number (84097440).

Almost surely, 2^656916509 is an apocalyptic number.

It is an amenable number.

656916509 is a deficient number, since it is larger than the sum of its proper divisors (15863011).

656916509 is a wasteful number, since it uses less digits than its factorization.

656916509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39339.

The product of its (nonzero) digits is 437400, while the sum is 47.

The square root of 656916509 is about 25630.3825371374. The cubic root of 656916509 is about 869.3007588908.

The spelling of 656916509 in words is "six hundred fifty-six million, nine hundred sixteen thousand, five hundred nine".