163651 has 4 divisors (see below), whose sum is σ = 168112. Its totient is φ = 159192.

The previous prime is 163643. The next prime is 163661. The reversal of 163651 is 156361.

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 163651 - 2³ = 163643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2175 + ... + 2248.

It is an arithmetic number, because the mean of its divisors is an integer number (42028).

2¹⁶³⁶⁵¹ is an apocalyptic number.

163651 is a deficient number, since it is larger than the sum of its proper divisors (4461).

163651 is an equidigital number, since it uses as much as digits as its factorization.

163651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4460.

The product of its digits is 540, while the sum is 22.

The square root of 163651 is about 404.5380081031. The cubic root of 163651 is about 54.6981814782.

It can be divided in two parts, 1636 and 51, that multiplied together give a triangular number (83436 = T₄₀₈).

The spelling of 163651 in words is "one hundred sixty-three thousand, six hundred fifty-one".