163967491 has 4 divisors (see below), whose sum is σ = 165164472. Its totient is φ = 162770512.

The previous prime is 163967477. The next prime is 163967513. The reversal of 163967491 is 194769361.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 163967491 - 2¹⁷ = 163836419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163965491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 598285 + ... + 598558.

It is an arithmetic number, because the mean of its divisors is an integer number (41291118).

Almost surely, 2^163967491 is an apocalyptic number.

163967491 is a deficient number, since it is larger than the sum of its proper divisors (1196981).

163967491 is a wasteful number, since it uses less digits than its factorization.

163967491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196980.

The product of its digits is 244944, while the sum is 46.

The square root of 163967491 is about 12804.9791487530. The cubic root of 163967491 is about 547.3341974815.

The spelling of 163967491 in words is "one hundred sixty-three million, nine hundred sixty-seven thousand, four hundred ninety-one".