65556561 has 16 divisors (see below), whose sum is σ = 101936000. Its totient is φ = 37460304.

The previous prime is 65556541. The next prime is 65556583. The reversal of 65556561 is 16565556.

It is not a de Polignac number, because 65556561 - 2⁵ = 65556529 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65556521) 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 15 ways as a sum of consecutive naturals, for example, 30826 + ... + 32883.

It is an arithmetic number, because the mean of its divisors is an integer number (6371000).

Almost surely, 2^65556561 is an apocalyptic number.

It is an amenable number.

65556561 is a deficient number, since it is larger than the sum of its proper divisors (36379439).

65556561 is an equidigital number, since it uses as much as digits as its factorization.

65556561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63733 (or 63719 counting only the distinct ones).

The product of its digits is 135000, while the sum is 39.

The square root of 65556561 is about 8096.7006243284. The cubic root of 65556561 is about 403.2168950289.

The spelling of 65556561 in words is "sixty-five million, five hundred fifty-six thousand, five hundred sixty-one".