77680205 has 8 divisors (see below), whose sum is σ = 95735832. Its totient is φ = 60464448.

The previous prime is 77680201. The next prime is 77680243. The reversal of 77680205 is 50208677.

It can be written as a sum of positive squares in 4 ways, for example, as 27071209 + 50608996 = 5203^2 + 7114^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 77680205 - 2² = 77680201 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77680201) 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, 209762 + ... + 210131.

It is an arithmetic number, because the mean of its divisors is an integer number (11966979).

Almost surely, 2^77680205 is an apocalyptic number.

It is an amenable number.

77680205 is a deficient number, since it is larger than the sum of its proper divisors (18055627).

77680205 is a wasteful number, since it uses less digits than its factorization.

77680205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419935.

The product of its (nonzero) digits is 23520, while the sum is 35.

The square root of 77680205 is about 8813.6374443246. The cubic root of 77680205 is about 426.6811474442.

The spelling of 77680205 in words is "seventy-seven million, six hundred eighty thousand, two hundred five".