64940809 has 8 divisors (see below), whose sum is σ = 67071368. Its totient is φ = 62830080.

The previous prime is 64940801. The next prime is 64940839. The reversal of 64940809 is 90804946.

It can be written as a sum of positive squares in 4 ways, for example, as 299209 + 64641600 = 547^2 + 8040^2 .

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 64940809 - 2³ = 64940801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64940801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1849 + ... + 11545.

It is an arithmetic number, because the mean of its divisors is an integer number (8383921).

Almost surely, 2^64940809 is an apocalyptic number.

It is an amenable number.

64940809 is a deficient number, since it is larger than the sum of its proper divisors (2130559).

64940809 is a wasteful number, since it uses less digits than its factorization.

64940809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9915.

The product of its (nonzero) digits is 62208, while the sum is 40.

The square root of 64940809 is about 8058.5860422285. The cubic root of 64940809 is about 401.9504922407.

The spelling of 64940809 in words is "sixty-four million, nine hundred forty thousand, eight hundred nine".