63891 has 12 divisors (see below), whose sum is σ = 95680. Its totient is φ = 41040.

The previous prime is 63863. The next prime is 63901. The reversal of 63891 is 19836.

It is not a de Polignac number, because 63891 - 2¹¹ = 61843 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (63841) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165 + ... + 393.

2⁶³⁸⁹¹ is an apocalyptic number.

63891 is a deficient number, since it is larger than the sum of its proper divisors (31789).

63891 is a wasteful number, since it uses less digits than its factorization.

63891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266 (or 263 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 63891 is about 252.7666908436. The cubic root of 63891 is about 39.9772787627.

It can be divided in two parts, 638 and 91, that added together give a 6-th power (729 = 3⁶).

The spelling of 63891 in words is "sixty-three thousand, eight hundred ninety-one".