509640668 has 6 divisors (see below), whose sum is σ = 891871176. Its totient is φ = 254820332.

The previous prime is 509640661. The next prime is 509640673. The reversal of 509640668 is 866046905.

It is a super-2 number, since 2×509640668² = 519467220958972448, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509640661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63705080 + ... + 63705087.

It is an arithmetic number, because the mean of its divisors is an integer number (148645196).

Almost surely, 2^509640668 is an apocalyptic number.

It is an amenable number.

509640668 is a deficient number, since it is larger than the sum of its proper divisors (382230508).

509640668 is a wasteful number, since it uses less digits than its factorization.

509640668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127410171 (or 127410169 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 44.

The square root of 509640668 is about 22575.2224352275. Note that the first 3 decimals coincide. The cubic root of 509640668 is about 798.7692889086.

The spelling of 509640668 in words is "five hundred nine million, six hundred forty thousand, six hundred sixty-eight".