77890565 has 4 divisors (see below), whose sum is σ = 93468684. Its totient is φ = 62312448.

The previous prime is 77890559. The next prime is 77890577. The reversal of 77890565 is 56509877.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 33721249 + 44169316 = 5807^2 + 6646^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77890565 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7789052 + ... + 7789061.

It is an arithmetic number, because the mean of its divisors is an integer number (23367171).

Almost surely, 2^77890565 is an apocalyptic number.

It is an amenable number.

77890565 is a deficient number, since it is larger than the sum of its proper divisors (15578119).

77890565 is a wasteful number, since it uses less digits than its factorization.

77890565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15578118.

The product of its (nonzero) digits is 529200, while the sum is 47.

The square root of 77890565 is about 8825.5631548361. The cubic root of 77890565 is about 427.0659548167.

The spelling of 77890565 in words is "seventy-seven million, eight hundred ninety thousand, five hundred sixty-five".