659280665521 has 3 divisors (see below), whose sum is σ = 659281477483. Its totient is φ = 659279853560.

The previous prime is 659280665513. The next prime is 659280665587. The reversal of 659280665521 is 125566082956.

The square root of 659280665521 is 811961.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 445207883121 + 214072782400 = 667239^2 + 462680^2 .

It is not a de Polignac number, because 659280665521 - 2³ = 659280665513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (659280665501) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 405981 + ... + 1217941.

Almost surely, 2^659280665521 is an apocalyptic number.

659280665521 is the 811961-st square number.

659280665521 is the 405981-st centered octagonal number.

It is an amenable number.

659280665521 is a deficient number, since it is larger than the sum of its proper divisors (811962).

659280665521 is an frugal number, since it uses more digits than its factorization.

659280665521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1623922 (or 811961 counting only the distinct ones).

The product of its (nonzero) digits is 7776000, while the sum is 55.

It can be divided in two parts, 659280 and 665521, that added together give a square (1324801 = 1151²).

The spelling of 659280665521 in words is "six hundred fifty-nine billion, two hundred eighty million, six hundred sixty-five thousand, five hundred twenty-one".