655544521 has 2 divisors, whose sum is σ = 655544522. Its totient is φ = 655544520.

The previous prime is 655544509. The next prime is 655544537. The reversal of 655544521 is 125445556.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 500193225 + 155351296 = 22365^2 + 12464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655544521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (655544581) 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 as a sum of consecutive naturals, namely, 327772260 + 327772261.

It is an arithmetic number, because the mean of its divisors is an integer number (327772261).

Almost surely, 2^655544521 is an apocalyptic number.

It is an amenable number.

655544521 is a deficient number, since it is larger than the sum of its proper divisors (1).

655544521 is an equidigital number, since it uses as much as digits as its factorization.

655544521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120000, while the sum is 37.

The square root of 655544521 is about 25603.6036721396. The cubic root of 655544521 is about 868.6951509909.

It can be divided in two parts, 6555 and 44521, that added together give a square (51076 = 226²).

The spelling of 655544521 in words is "six hundred fifty-five million, five hundred forty-four thousand, five hundred twenty-one".