64136909 has 4 divisors (see below), whose sum is σ = 64199100. Its totient is φ = 64074720.

The previous prime is 64136899. The next prime is 64136911. The reversal of 64136909 is 90963146.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60016009 + 4120900 = 7747^2 + 2030^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64136909 is a prime.

It is a super-2 number, since 2×64136909² = 8227086192148562, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64136929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29522 + ... + 31619.

It is an arithmetic number, because the mean of its divisors is an integer number (16049775).

Almost surely, 2^64136909 is an apocalyptic number.

It is an amenable number.

64136909 is a deficient number, since it is larger than the sum of its proper divisors (62191).

64136909 is a wasteful number, since it uses less digits than its factorization.

64136909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62190.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 64136909 is about 8008.5522411982. The cubic root of 64136909 is about 400.2850239385.

The spelling of 64136909 in words is "sixty-four million, one hundred thirty-six thousand, nine hundred nine".