509351661 has 96 divisors (see below), whose sum is σ = 939294720. Its totient is φ = 258878592.

The previous prime is 509351627. The next prime is 509351663. The reversal of 509351661 is 166153905.

509351661 is a `hidden beast` number, since 50 + 93 + 516 + 6 + 1 = 666.

It is not a de Polignac number, because 509351661 - 2⁶ = 509351597 is a prime.

It is a super-2 number, since 2×509351661² = 518878229126917842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509351663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4010580 + ... + 4010706.

It is an arithmetic number, because the mean of its divisors is an integer number (9784320).

Almost surely, 2^509351661 is an apocalyptic number.

It is an amenable number.

509351661 is a deficient number, since it is larger than the sum of its proper divisors (429943059).

509351661 is a wasteful number, since it uses less digits than its factorization.

509351661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 292 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 509351661 is about 22568.8205495990. The cubic root of 509351661 is about 798.6182716783.

The spelling of 509351661 in words is "five hundred nine million, three hundred fifty-one thousand, six hundred sixty-one".