64943209 has 8 divisors (see below), whose sum is σ = 68105160. Its totient is φ = 61842816.

The previous prime is 64943189. The next prime is 64943227. The reversal of 64943209 is 90234946.

It can be written as a sum of positive squares in 4 ways, for example, as 18662400 + 46280809 = 4320^2 + 6803^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64943209 - 2²¹ = 62846057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64943239) 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 7 ways as a sum of consecutive naturals, for example, 13222 + ... + 17455.

It is an arithmetic number, because the mean of its divisors is an integer number (8513145).

Almost surely, 2^64943209 is an apocalyptic number.

It is an amenable number.

64943209 is a deficient number, since it is larger than the sum of its proper divisors (3161951).

64943209 is a wasteful number, since it uses less digits than its factorization.

64943209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30779.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 64943209 is about 8058.7349503505. The cubic root of 64943209 is about 401.9554437717.

The spelling of 64943209 in words is "sixty-four million, nine hundred forty-three thousand, two hundred nine".