64523665 has 16 divisors (see below), whose sum is σ = 79615440. Its totient is φ = 50181120.

The previous prime is 64523647. The next prime is 64523699. The reversal of 64523665 is 56632546.

64523665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 20061441 + 44462224 = 4479^2 + 6668^2 .

It is not a de Polignac number, because 64523665 - 2⁵ = 64523633 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25957 + ... + 28333.

It is an arithmetic number, because the mean of its divisors is an integer number (4975965).

Almost surely, 2^64523665 is an apocalyptic number.

It is an amenable number.

64523665 is a deficient number, since it is larger than the sum of its proper divisors (15091775).

64523665 is a wasteful number, since it uses less digits than its factorization.

64523665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2532.

The product of its digits is 129600, while the sum is 37.

The square root of 64523665 is about 8032.6623855357. The cubic root of 64523665 is about 401.0880066705.

It can be divided in two parts, 645 and 23665, that added together give a triangular number (24310 = T₂₂₀).

The spelling of 64523665 in words is "sixty-four million, five hundred twenty-three thousand, six hundred sixty-five".