163991534 has 24 divisors (see below), whose sum is σ = 286597368. Its totient is φ = 70171920.

The previous prime is 163991533. The next prime is 163991539. The reversal of 163991534 is 435199361.

It is a junction number, because it is equal to n+sod(n) for n = 163991491 and 163991500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163991533) 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 11 ways as a sum of consecutive naturals, for example, 106349 + ... + 107879.

It is an arithmetic number, because the mean of its divisors is an integer number (11941557).

Almost surely, 2^163991534 is an apocalyptic number.

163991534 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

163991534 is a deficient number, since it is larger than the sum of its proper divisors (122605834).

163991534 is a wasteful number, since it uses less digits than its factorization.

163991534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2640 (or 2633 counting only the distinct ones).

The product of its digits is 87480, while the sum is 41.

The square root of 163991534 is about 12805.9179288327. The cubic root of 163991534 is about 547.3609485423.

The spelling of 163991534 in words is "one hundred sixty-three million, nine hundred ninety-one thousand, five hundred thirty-four".