1646336561 has 8 divisors (see below), whose sum is σ = 1715330304. Its totient is φ = 1578335760.

The previous prime is 1646336543. The next prime is 1646336581. The reversal of 1646336561 is 1656336461.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1646336561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1646336501) 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, 244850 + ... + 251483.

It is an arithmetic number, because the mean of its divisors is an integer number (214416288).

Almost surely, 2^1646336561 is an apocalyptic number.

It is an amenable number.

1646336561 is a deficient number, since it is larger than the sum of its proper divisors (68993743).

1646336561 is a wasteful number, since it uses less digits than its factorization.

1646336561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 496471.

The product of its digits is 233280, while the sum is 41.

The square root of 1646336561 is about 40575.0731484245. The cubic root of 1646336561 is about 1180.7905649791.

The spelling of 1646336561 in words is "one billion, six hundred forty-six million, three hundred thirty-six thousand, five hundred sixty-one".