61665665 has 16 divisors (see below), whose sum is σ = 76640256. Its totient is φ = 47582400.

The previous prime is 61665619. The next prime is 61665673. The reversal of 61665665 is 56656616.

61665665 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61665665 - 2²² = 57471361 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 71024 + ... + 71886.

It is an arithmetic number, because the mean of its divisors is an integer number (4790016).

Almost surely, 2^61665665 is an apocalyptic number.

It is an amenable number.

61665665 is a deficient number, since it is larger than the sum of its proper divisors (14974591).

61665665 is a wasteful number, since it uses less digits than its factorization.

61665665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360.

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

The square root of 61665665 is about 7852.7488817611. The cubic root of 61665665 is about 395.0764473091.

The spelling of 61665665 in words is "sixty-one million, six hundred sixty-five thousand, six hundred sixty-five".