64637909 has 12 divisors (see below), whose sum is σ = 75322764. Its totient is φ = 55306944.

The previous prime is 64637891. The next prime is 64637917. The reversal of 64637909 is 90973646.

It can be written as a sum of positive squares in 2 ways, for example, as 54538225 + 10099684 = 7385^2 + 3178^2 .

It is not a de Polignac number, because 64637909 - 2⁸ = 64637653 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64637909.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64637939) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 49979 + ... + 51255.

It is an arithmetic number, because the mean of its divisors is an integer number (6276897).

Almost surely, 2^64637909 is an apocalyptic number.

It is an amenable number.

64637909 is a deficient number, since it is larger than the sum of its proper divisors (10684855).

64637909 is a wasteful number, since it uses less digits than its factorization.

64637909 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2324 (or 2317 counting only the distinct ones).

The product of its (nonzero) digits is 244944, while the sum is 44.

The square root of 64637909 is about 8039.7704569223. The cubic root of 64637909 is about 401.3245859220.

The spelling of 64637909 in words is "sixty-four million, six hundred thirty-seven thousand, nine hundred nine".