64491 has 16 divisors (see below), whose sum is σ = 102144. Its totient is φ = 35424.

The previous prime is 64489. The next prime is 64499. The reversal of 64491 is 19446.

It is not a de Polignac number, because 64491 - 2¹ = 64489 is a prime.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64499) 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 15 ways as a sum of consecutive naturals, for example, 736 + ... + 818.

It is an arithmetic number, because the mean of its divisors is an integer number (6384).

2⁶⁴⁴⁹¹ is an apocalyptic number.

64491 is a deficient number, since it is larger than the sum of its proper divisors (37653).

64491 is a wasteful number, since it uses less digits than its factorization.

64491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130.

The product of its digits is 864, while the sum is 24.

The square root of 64491 is about 253.9507826332. The cubic root of 64491 is about 40.1020311863.

It can be divided in two parts, 64 and 491, that added together give a palindrome (555).

The spelling of 64491 in words is "sixty-four thousand, four hundred ninety-one".