65778385 has 4 divisors (see below), whose sum is σ = 78934068. Its totient is φ = 52622704.

The previous prime is 65778343. The next prime is 65778397. The reversal of 65778385 is 58387756.

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 15311569 + 50466816 = 3913^2 + 7104^2 .

It is a cyclic number.

It is not a de Polignac number, because 65778385 - 2¹³ = 65770193 is a prime.

It is a Duffinian 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, 6577834 + ... + 6577843.

It is an arithmetic number, because the mean of its divisors is an integer number (19733517).

Almost surely, 2^65778385 is an apocalyptic number.

It is an amenable number.

65778385 is a deficient number, since it is larger than the sum of its proper divisors (13155683).

65778385 is a wasteful number, since it uses less digits than its factorization.

65778385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13155682.

The product of its digits is 1411200, while the sum is 49.

The square root of 65778385 is about 8110.3874753306. The cubic root of 65778385 is about 403.6711719123.

The spelling of 65778385 in words is "sixty-five million, seven hundred seventy-eight thousand, three hundred eighty-five".