163509813 has 8 divisors (see below), whose sum is σ = 242236800. Its totient is φ = 109006524.

The previous prime is 163509799. The next prime is 163509817. The reversal of 163509813 is 318905361.

It is a happy number.

163509813 is a `hidden beast` number, since 1 + 635 + 0 + 9 + 8 + 13 = 666.

It is not a de Polignac number, because 163509813 - 2⁸ = 163509557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163509817) 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, 3027933 + ... + 3027986.

It is an arithmetic number, because the mean of its divisors is an integer number (30279600).

Almost surely, 2^163509813 is an apocalyptic number.

It is an amenable number.

163509813 is a deficient number, since it is larger than the sum of its proper divisors (78726987).

163509813 is an equidigital number, since it uses as much as digits as its factorization.

163509813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6055928 (or 6055922 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 163509813 is about 12787.0955654519. The cubic root of 163509813 is about 546.8244699022.

The spelling of 163509813 in words is "one hundred sixty-three million, five hundred nine thousand, eight hundred thirteen".