163506993 has 24 divisors (see below), whose sum is σ = 236904480. Its totient is φ = 100264320.

The previous prime is 163506991. The next prime is 163507073. The reversal of 163506993 is 399605361.

It is not a de Polignac number, because 163506993 - 2¹ = 163506991 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (163506991) 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 23 ways as a sum of consecutive naturals, for example, 263838 + ... + 264456.

It is an arithmetic number, because the mean of its divisors is an integer number (9871020).

Almost surely, 2^163506993 is an apocalyptic number.

163506993 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

163506993 is a deficient number, since it is larger than the sum of its proper divisors (73397487).

163506993 is a wasteful number, since it uses less digits than its factorization.

163506993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1169 (or 1156 counting only the distinct ones).

The product of its (nonzero) digits is 131220, while the sum is 42.

The square root of 163506993 is about 12786.9852975594. The cubic root of 163506993 is about 546.8213262501.

The spelling of 163506993 in words is "one hundred sixty-three million, five hundred six thousand, nine hundred ninety-three".