659821969 has 9 divisors (see below), whose sum is σ = 701382331. Its totient is φ = 620597920.

The previous prime is 659821951. The next prime is 659821973. The reversal of 659821969 is 969128956.

It is a happy number.

The square root of 659821969 is 25687.

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

It can be written as a sum of positive squares in only one way, i.e., 513702225 + 146119744 = 22665^2 + 12088^2 .

It is not a de Polignac number, because 659821969 - 2⁵ = 659821937 is a prime.

It is a super-2 number, since 2×659821969² = 870730061550073922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (659821909) 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 8 ways as a sum of consecutive naturals, for example, 435924 + ... + 437434.

Almost surely, 2^659821969 is an apocalyptic number.

659821969 is the 25687-th square number.

659821969 is the 12844-th centered octagonal number.

It is an amenable number.

659821969 is a deficient number, since it is larger than the sum of its proper divisors (41560362).

659821969 is an frugal number, since it uses more digits than its factorization.

659821969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3056 (or 1528 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 55.

The cubic root of 659821969 is about 870.5804771019.

The spelling of 659821969 in words is "six hundred fifty-nine million, eight hundred twenty-one thousand, nine hundred sixty-nine".