77205985 has 4 divisors (see below), whose sum is σ = 92647188. Its totient is φ = 61764784.

The previous prime is 77205979. The next prime is 77205991. The reversal of 77205985 is 58950277.

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

It is an interprime number because it is at equal distance from previous prime (77205979) and next prime (77205991).

It can be written as a sum of positive squares in 2 ways, for example, as 55935441 + 21270544 = 7479^2 + 4612^2 .

It is a cyclic number.

It is not a de Polignac number, because 77205985 - 2³ = 77205977 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, 7720594 + ... + 7720603.

It is an arithmetic number, because the mean of its divisors is an integer number (23161797).

Almost surely, 2^77205985 is an apocalyptic number.

It is an amenable number.

77205985 is a deficient number, since it is larger than the sum of its proper divisors (15441203).

77205985 is a wasteful number, since it uses less digits than its factorization.

77205985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15441202.

The product of its (nonzero) digits is 176400, while the sum is 43.

The square root of 77205985 is about 8786.6936329885. The cubic root of 77205985 is about 425.8111107599.

The spelling of 77205985 in words is "seventy-seven million, two hundred five thousand, nine hundred eighty-five".