77668009 has 2 divisors, whose sum is σ = 77668010. Its totient is φ = 77668008.

The previous prime is 77668007. The next prime is 77668021. The reversal of 77668009 is 90086677.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60403984 + 17264025 = 7772^2 + 4155^2 .

It is a cyclic number.

It is not a de Polignac number, because 77668009 - 2¹ = 77668007 is a prime.

Together with 77668007, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (77668007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38834004 + 38834005.

It is an arithmetic number, because the mean of its divisors is an integer number (38834005).

Almost surely, 2^77668009 is an apocalyptic number.

It is an amenable number.

77668009 is a deficient number, since it is larger than the sum of its proper divisors (1).

77668009 is an equidigital number, since it uses as much as digits as its factorization.

77668009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 127008, while the sum is 43.

The square root of 77668009 is about 8812.9455348368. The cubic root of 77668009 is about 426.6588162482.

The spelling of 77668009 in words is "seventy-seven million, six hundred sixty-eight thousand, nine".