64551665 has 8 divisors (see below), whose sum is σ = 77801640. Its totient is φ = 51414912.

The previous prime is 64551647. The next prime is 64551667. The reversal of 64551665 is 56615546.

It can be written as a sum of positive squares in 4 ways, for example, as 4194304 + 60357361 = 2048^2 + 7769^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64551665 - 2¹⁶ = 64486129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (64551667) 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 7 ways as a sum of consecutive naturals, for example, 27044 + ... + 29333.

It is an arithmetic number, because the mean of its divisors is an integer number (9725205).

Almost surely, 2^64551665 is an apocalyptic number.

It is an amenable number.

64551665 is a deficient number, since it is larger than the sum of its proper divisors (13249975).

64551665 is a wasteful number, since it uses less digits than its factorization.

64551665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56611.

The product of its digits is 108000, while the sum is 38.

The square root of 64551665 is about 8034.4050806516. The cubic root of 64551665 is about 401.1460155685.

The spelling of 64551665 in words is "sixty-four million, five hundred fifty-one thousand, six hundred sixty-five".