63491 has 4 divisors (see below), whose sum is σ = 64032. Its totient is φ = 62952.

The previous prime is 63487. The next prime is 63493. The reversal of 63491 is 19436.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 63491 - 2² = 63487 is a prime.

It is a super-2 number, since 2×63491² = 8062214162, which contains 22 as substring.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11 + ... + 356.

It is an arithmetic number, because the mean of its divisors is an integer number (16008).

2⁶³⁴⁹¹ is an apocalyptic number.

63491 is a deficient number, since it is larger than the sum of its proper divisors (541).

63491 is a wasteful number, since it uses less digits than its factorization.

63491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 540.

The product of its digits is 648, while the sum is 23.

The square root of 63491 is about 251.9742050290. The cubic root of 63491 is about 39.8936759637.

The spelling of 63491 in words is "sixty-three thousand, four hundred ninety-one".