76720665 has 32 divisors (see below), whose sum is σ = 141039360. Its totient is φ = 34884864.

The previous prime is 76720661. The next prime is 76720681. The reversal of 76720665 is 56602767.

It is not a de Polignac number, because 76720665 - 2² = 76720661 is a prime.

It is not an unprimeable number, because it can be changed into a prime (76720661) 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 31 ways as a sum of consecutive naturals, for example, 18831 + ... + 22539.

It is an arithmetic number, because the mean of its divisors is an integer number (4407480).

Almost surely, 2^76720665 is an apocalyptic number.

It is an amenable number.

76720665 is a deficient number, since it is larger than the sum of its proper divisors (64318695).

76720665 is a wasteful number, since it uses less digits than its factorization.

76720665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3921.

The product of its (nonzero) digits is 105840, while the sum is 39.

The square root of 76720665 is about 8759.0333370755. The cubic root of 76720665 is about 424.9170126316.

The spelling of 76720665 in words is "seventy-six million, seven hundred twenty thousand, six hundred sixty-five".