646604440 has 32 divisors (see below), whose sum is σ = 1490348160. Its totient is φ = 252332800.

The previous prime is 646604437. The next prime is 646604443. The reversal of 646604440 is 44406646.

It is an interprime number because it is at equal distance from previous prime (646604437) and next prime (646604443).

It is a junction number, because it is equal to n+sod(n) for n = 646604396 and 646604405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646604443) 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 7 ways as a sum of consecutive naturals, for example, 195496 + ... + 198775.

It is an arithmetic number, because the mean of its divisors is an integer number (46573380).

Almost surely, 2^646604440 is an apocalyptic number.

It is an amenable number.

646604440 is an abundant number, since it is smaller than the sum of its proper divisors (843743720).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646604440 is a wasteful number, since it uses less digits than its factorization.

646604440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394323 (or 394319 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 34.

The square root of 646604440 is about 25428.4179610136. The cubic root of 646604440 is about 864.7280778471.

The spelling of 646604440 in words is "six hundred forty-six million, six hundred four thousand, four hundred forty".