63891161 has 4 divisors (see below), whose sum is σ = 65449524. Its totient is φ = 62332800.

The previous prime is 63891143. The next prime is 63891173. The reversal of 63891161 is 16119836.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30030400 + 33860761 = 5480^2 + 5819^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63891161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63891101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 779120 + ... + 779201.

It is an arithmetic number, because the mean of its divisors is an integer number (16362381).

Almost surely, 2^63891161 is an apocalyptic number.

It is an amenable number.

63891161 is a deficient number, since it is larger than the sum of its proper divisors (1558363).

63891161 is a wasteful number, since it uses less digits than its factorization.

63891161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1558362.

The product of its digits is 7776, while the sum is 35.

The square root of 63891161 is about 7993.1946679660. The cubic root of 63891161 is about 399.7731234252.

The spelling of 63891161 in words is "sixty-three million, eight hundred ninety-one thousand, one hundred sixty-one".