65656661 has 4 divisors (see below), whose sum is σ = 75036192. Its totient is φ = 56277132.

The previous prime is 65656649. The next prime is 65656687. The reversal of 65656661 is 16665656.

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 65656661 - 2⁶ = 65656597 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65656631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4689755 + ... + 4689768.

It is an arithmetic number, because the mean of its divisors is an integer number (18759048).

Almost surely, 2^65656661 is an apocalyptic number.

It is an amenable number.

65656661 is a deficient number, since it is larger than the sum of its proper divisors (9379531).

65656661 is an equidigital number, since it uses as much as digits as its factorization.

65656661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9379530.

The product of its digits is 194400, while the sum is 41.

The square root of 65656661 is about 8102.8797967143. The cubic root of 65656661 is about 403.4220180795.

The spelling of 65656661 in words is "sixty-five million, six hundred fifty-six thousand, six hundred sixty-one".