76643309 has 8 divisors (see below), whose sum is σ = 78773688. Its totient is φ = 74525440.

The previous prime is 76643299. The next prime is 76643339. The reversal of 76643309 is 90334667.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 570025 + 76073284 = 755^2 + 8722^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-76643309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76643339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10049 + ... + 15945.

It is an arithmetic number, because the mean of its divisors is an integer number (9846711).

Almost surely, 2^76643309 is an apocalyptic number.

It is an amenable number.

76643309 is a deficient number, since it is larger than the sum of its proper divisors (2130379).

76643309 is a wasteful number, since it uses less digits than its factorization.

76643309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6255.

The product of its (nonzero) digits is 81648, while the sum is 38.

The square root of 76643309 is about 8754.6164393422. The cubic root of 76643309 is about 424.7741526691.

The spelling of 76643309 in words is "seventy-six million, six hundred forty-three thousand, three hundred nine".