64807891 has 4 divisors (see below), whose sum is σ = 64827000. Its totient is φ = 64788784.

The previous prime is 64807861. The next prime is 64807907. The reversal of 64807891 is 19870846.

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 64807891 - 2¹¹ = 64805843 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64807801) 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, 2941 + ... + 11758.

It is an arithmetic number, because the mean of its divisors is an integer number (16206750).

Almost surely, 2^64807891 is an apocalyptic number.

64807891 is a deficient number, since it is larger than the sum of its proper divisors (19109).

64807891 is a wasteful number, since it uses less digits than its factorization.

64807891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19108.

The product of its (nonzero) digits is 96768, while the sum is 43.

The square root of 64807891 is about 8050.3348377568. The cubic root of 64807891 is about 401.6760733857.

The spelling of 64807891 in words is "sixty-four million, eight hundred seven thousand, eight hundred ninety-one".