653381665 has 4 divisors (see below), whose sum is σ = 784058004. Its totient is φ = 522705328.

The previous prime is 653381647. The next prime is 653381693. The reversal of 653381665 is 566183356.

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 394300449 + 259081216 = 19857^2 + 16096^2 .

It is a cyclic number.

It is not a de Polignac number, because 653381665 - 2¹⁹ = 652857377 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 65338162 + ... + 65338171.

It is an arithmetic number, because the mean of its divisors is an integer number (196014501).

Almost surely, 2^653381665 is an apocalyptic number.

It is an amenable number.

653381665 is a deficient number, since it is larger than the sum of its proper divisors (130676339).

653381665 is a wasteful number, since it uses less digits than its factorization.

653381665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130676338.

The product of its digits is 388800, while the sum is 43.

The square root of 653381665 is about 25561.3314402830. The cubic root of 653381665 is about 867.7387284634.

It can be divided in two parts, 6533 and 81665, that multiplied together give a triangular number (533517445 = T₃₂₆₆₅).

The spelling of 653381665 in words is "six hundred fifty-three million, three hundred eighty-one thousand, six hundred sixty-five".