63968591 has 4 divisors (see below), whose sum is σ = 64778400. Its totient is φ = 63158784.

The previous prime is 63968561. The next prime is 63968599. The reversal of 63968591 is 19586936.

63968591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 63968591 - 2¹⁰ = 63967567 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63968599) 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 3 ways as a sum of consecutive naturals, for example, 404786 + ... + 404943.

It is an arithmetic number, because the mean of its divisors is an integer number (16194600).

Almost surely, 2^63968591 is an apocalyptic number.

63968591 is a deficient number, since it is larger than the sum of its proper divisors (809809).

63968591 is an equidigital number, since it uses as much as digits as its factorization.

63968591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809808.

The product of its digits is 349920, while the sum is 47.

The square root of 63968591 is about 7998.0366965900. The cubic root of 63968591 is about 399.9345538759.

The spelling of 63968591 in words is "sixty-three million, nine hundred sixty-eight thousand, five hundred ninety-one".