646503009 has 4 divisors (see below), whose sum is σ = 862004016. Its totient is φ = 431002004.

The previous prime is 646502971. The next prime is 646503023. The reversal of 646503009 is 900305646.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 646503009 - 2¹⁵ = 646470241 is a prime.

It is a super-2 number, since 2×646503009² = 835932281292108162, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (646503049) 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 3 ways as a sum of consecutive naturals, for example, 107750499 + ... + 107750504.

It is an arithmetic number, because the mean of its divisors is an integer number (215501004).

Almost surely, 2^646503009 is an apocalyptic number.

It is an amenable number.

646503009 is a deficient number, since it is larger than the sum of its proper divisors (215501007).

646503009 is a wasteful number, since it uses less digits than its factorization.

646503009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215501006.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 646503009 is about 25426.4234409797. The cubic root of 646503009 is about 864.6828596710.

The spelling of 646503009 in words is "six hundred forty-six million, five hundred three thousand, nine".