64543391 has 4 divisors (see below), whose sum is σ = 70410984. Its totient is φ = 58675800.

The previous prime is 64543337. The next prime is 64543397. The reversal of 64543391 is 19334546.

It is a happy number.

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 64543391 - 2⁶ = 64543327 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 (64543397) 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, 2933780 + ... + 2933801.

It is an arithmetic number, because the mean of its divisors is an integer number (17602746).

Almost surely, 2^64543391 is an apocalyptic number.

64543391 is a deficient number, since it is larger than the sum of its proper divisors (5867593).

64543391 is a wasteful number, since it uses less digits than its factorization.

64543391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5867592.

The product of its digits is 38880, while the sum is 35.

The square root of 64543391 is about 8033.8901535931. The cubic root of 64543391 is about 401.1288756855.

The spelling of 64543391 in words is "sixty-four million, five hundred forty-three thousand, three hundred ninety-one".