163891 has 8 divisors (see below), whose sum is σ = 201824. Its totient is φ = 129600.

The previous prime is 163883. The next prime is 163901. The reversal of 163891 is 198361.

163891 = 150² + 151² + ... + 156².

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 6-Lehmer number, since φ(163891) divides (163891-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 163891 - 2³ = 163883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (163811) 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, 810 + ... + 991.

It is an arithmetic number, because the mean of its divisors is an integer number (25228).

2¹⁶³⁸⁹¹ is an apocalyptic number.

163891 is a deficient number, since it is larger than the sum of its proper divisors (37933).

163891 is a wasteful number, since it uses less digits than its factorization.

163891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1821.

The product of its digits is 1296, while the sum is 28.

The square root of 163891 is about 404.8345341000. The cubic root of 163891 is about 54.7249073592.

The spelling of 163891 in words is "one hundred sixty-three thousand, eight hundred ninety-one".