66605365 has 16 divisors (see below), whose sum is σ = 83647728. Its totient is φ = 50858496.

The previous prime is 66605339. The next prime is 66605369. The reversal of 66605365 is 56350666.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 117649 + 66487716 = 343^2 + 8154^2 .

It is a cyclic number.

It is not a de Polignac number, because 66605365 - 2⁵ = 66605333 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66605369) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6409 + ... + 13201.

It is an arithmetic number, because the mean of its divisors is an integer number (5227983).

Almost surely, 2^66605365 is an apocalyptic number.

It is an amenable number.

66605365 is a deficient number, since it is larger than the sum of its proper divisors (17042363).

66605365 is a wasteful number, since it uses less digits than its factorization.

66605365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6888.

The product of its (nonzero) digits is 97200, while the sum is 37.

The square root of 66605365 is about 8161.2110008258. The cubic root of 66605365 is about 405.3558118852.

The spelling of 66605365 in words is "sixty-six million, six hundred five thousand, three hundred sixty-five".