64936561 has 4 divisors (see below), whose sum is σ = 64968192. Its totient is φ = 64904932.

The previous prime is 64936483. The next prime is 64936589. The reversal of 64936561 is 16563946.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64936561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64939561) 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, 12505 + ... + 16918.

It is an arithmetic number, because the mean of its divisors is an integer number (16242048).

Almost surely, 2^64936561 is an apocalyptic number.

It is an amenable number.

64936561 is a deficient number, since it is larger than the sum of its proper divisors (31631).

64936561 is a wasteful number, since it uses less digits than its factorization.

64936561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31630.

The product of its digits is 116640, while the sum is 40.

The square root of 64936561 is about 8058.3224681071. The cubic root of 64936561 is about 401.9417277316.

The spelling of 64936561 in words is "sixty-four million, nine hundred thirty-six thousand, five hundred sixty-one".