646590561 has 8 divisors (see below), whose sum is σ = 863529600. Its totient is φ = 430355952.

The previous prime is 646590557. The next prime is 646590569. The reversal of 646590561 is 165095646.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 646590561 - 2² = 646590557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (646590569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 173961 + ... + 177638.

It is an arithmetic number, because the mean of its divisors is an integer number (107941200).

Almost surely, 2^646590561 is an apocalyptic number.

It is an amenable number.

646590561 is a deficient number, since it is larger than the sum of its proper divisors (216939039).

646590561 is a wasteful number, since it uses less digits than its factorization.

646590561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352215.

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 646590561 is about 25428.1450562167. The cubic root of 646590561 is about 864.7218908359.

The spelling of 646590561 in words is "six hundred forty-six million, five hundred ninety thousand, five hundred sixty-one".