64143209 has 4 divisors (see below), whose sum is σ = 69077316. Its totient is φ = 59209104.

The previous prime is 64143179. The next prime is 64143217. The reversal of 64143209 is 90234146.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90234146 = 2 ⋅45117073.

It can be written as a sum of positive squares in 2 ways, for example, as 4853209 + 59290000 = 2203^2 + 7700^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64143209 is a prime.

It is a super-2 number, since 2×64143209² = 8228702521635362, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (64143239) 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, 2467034 + ... + 2467059.

It is an arithmetic number, because the mean of its divisors is an integer number (17269329).

Almost surely, 2^64143209 is an apocalyptic number.

It is an amenable number.

64143209 is a deficient number, since it is larger than the sum of its proper divisors (4934107).

64143209 is a wasteful number, since it uses less digits than its factorization.

64143209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4934106.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 64143209 is about 8008.9455610586. The cubic root of 64143209 is about 400.2981298246.

The spelling of 64143209 in words is "sixty-four million, one hundred forty-three thousand, two hundred nine".