76661665 has 4 divisors (see below), whose sum is σ = 91994004. Its totient is φ = 61329328.

The previous prime is 76661659. The next prime is 76661693. The reversal of 76661665 is 56616667.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 25796241 + 50865424 = 5079^2 + 7132^2 .

It is a cyclic number.

It is not a de Polignac number, because 76661665 - 2³ = 76661657 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 (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7666162 + ... + 7666171.

It is an arithmetic number, because the mean of its divisors is an integer number (22998501).

Almost surely, 2^76661665 is an apocalyptic number.

It is an amenable number.

76661665 is a deficient number, since it is larger than the sum of its proper divisors (15332339).

76661665 is a wasteful number, since it uses less digits than its factorization.

76661665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15332338.

The product of its digits is 272160, while the sum is 43.

The square root of 76661665 is about 8755.6647377569. The cubic root of 76661665 is about 424.8080609648.

The spelling of 76661665 in words is "seventy-six million, six hundred sixty-one thousand, six hundred sixty-five".