65603521 has 4 divisors (see below), whose sum is σ = 68455872. Its totient is φ = 62751172.

The previous prime is 65603513. The next prime is 65603537. The reversal of 65603521 is 12530656.

65603521 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65603521 - 2³ = 65603513 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 65603521.

It is not an unprimeable number, because it can be changed into a prime (65603821) by changing a digit.

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, 1426141 + ... + 1426186.

It is an arithmetic number, because the mean of its divisors is an integer number (17113968).

Almost surely, 2^65603521 is an apocalyptic number.

It is an amenable number.

65603521 is a deficient number, since it is larger than the sum of its proper divisors (2852351).

65603521 is a wasteful number, since it uses less digits than its factorization.

65603521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2852350.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 65603521 is about 8099.6000518544. The cubic root of 65603521 is about 403.3131505659.

The spelling of 65603521 in words is "sixty-five million, six hundred three thousand, five hundred twenty-one".