63891071 has 4 divisors (see below), whose sum is σ = 63937272. Its totient is φ = 63844872.

The previous prime is 63891067. The next prime is 63891073. The reversal of 63891071 is 17019836.

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 63891071 - 2² = 63891067 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 (63891073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20960 + ... + 23813.

It is an arithmetic number, because the mean of its divisors is an integer number (15984318).

Almost surely, 2^63891071 is an apocalyptic number.

63891071 is a deficient number, since it is larger than the sum of its proper divisors (46201).

63891071 is a wasteful number, since it uses less digits than its factorization.

63891071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46200.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 63891071 is about 7993.1890381749. The cubic root of 63891071 is about 399.7729357122.

The spelling of 63891071 in words is "sixty-three million, eight hundred ninety-one thousand, seventy-one".