646153922569 has 9 divisors (see below), whose sum is σ = 650948517453. Its totient is φ = 641394403692.

The previous prime is 646153922567. The next prime is 646153922593. The reversal of 646153922569 is 965229351646.

The square root of 646153922569 is 803837.

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

It is not a de Polignac number, because 646153922569 - 2¹ = 646153922567 is a prime.

It is a super-2 number, since 2×646153922569² (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 (646153922567) 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, 111730452 + ... + 111736234.

Almost surely, 2^646153922569 is an apocalyptic number.

646153922569 is the 803837-th square number.

646153922569 is the 401919-th centered octagonal number.

It is an amenable number.

646153922569 is a deficient number, since it is larger than the sum of its proper divisors (4794594884).

646153922569 is an frugal number, since it uses more digits than its factorization.

646153922569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11844 (or 5922 counting only the distinct ones).

The product of its digits is 20995200, while the sum is 58.

The spelling of 646153922569 in words is "six hundred forty-six billion, one hundred fifty-three million, nine hundred twenty-two thousand, five hundred sixty-nine".