655304821081 has 9 divisors (see below), whose sum is σ = 657309602173. Its totient is φ = 653306143360.

The previous prime is 655304821063. The next prime is 655304821109. The reversal of 655304821081 is 180128403556.

The square root of 655304821081 is 809509.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 99534571081 + 555770250000 = 315491^2 + 745500^2 .

It is not a de Polignac number, because 655304821081 - 2¹³ = 655304812889 is a prime.

It is a super-2 number, since 2×655304821081² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (655304821001) 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 8 ways as a sum of consecutive naturals, for example, 314897961 + ... + 314900041.

Almost surely, 2^655304821081 is an apocalyptic number.

655304821081 is the 809509-th square number.

655304821081 is the 404755-th centered octagonal number.

It is an amenable number.

655304821081 is a deficient number, since it is larger than the sum of its proper divisors (2004781092).

655304821081 is an frugal number, since it uses more digits than its factorization.

655304821081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4940 (or 2470 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 43.

The spelling of 655304821081 in words is "six hundred fifty-five billion, three hundred four million, eight hundred twenty-one thousand, eighty-one".