65688057649 has 4 divisors (see below), whose sum is σ = 66021499764. Its totient is φ = 65354615536.

The previous prime is 65688057641. The next prime is 65688057653. The reversal of 65688057649 is 94675088656.

65688057649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 41622120225 + 24065937424 = 204015^2 + 155132^2 .

It is a cyclic number.

It is not a de Polignac number, because 65688057649 - 2³ = 65688057641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65688057641) 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, 166720762 + ... + 166721155.

It is an arithmetic number, because the mean of its divisors is an integer number (16505374941).

Almost surely, 2^65688057649 is an apocalyptic number.

It is an amenable number.

65688057649 is a deficient number, since it is larger than the sum of its proper divisors (333442115).

65688057649 is a wasteful number, since it uses less digits than its factorization.

65688057649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333442114.

The product of its (nonzero) digits is 87091200, while the sum is 64.

The spelling of 65688057649 in words is "sixty-five billion, six hundred eighty-eight million, fifty-seven thousand, six hundred forty-nine".