66783785 has 8 divisors (see below), whose sum is σ = 80357640. Its totient is φ = 53282304.

The previous prime is 66783767. The next prime is 66783797. The reversal of 66783785 is 58738766.

It can be written as a sum of positive squares in 4 ways, for example, as 7678441 + 59105344 = 2771^2 + 7688^2 .

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

It is not a de Polignac number, because 66783785 - 2²⁴ = 50006569 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16040 + ... + 19769.

It is an arithmetic number, because the mean of its divisors is an integer number (10044705).

Almost surely, 2^66783785 is an apocalyptic number.

It is an amenable number.

66783785 is a deficient number, since it is larger than the sum of its proper divisors (13573855).

66783785 is a wasteful number, since it uses less digits than its factorization.

66783785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36187.

The product of its digits is 1693440, while the sum is 50.

The square root of 66783785 is about 8172.1346660466. The cubic root of 66783785 is about 405.7174399144.

The spelling of 66783785 in words is "sixty-six million, seven hundred eighty-three thousand, seven hundred eighty-five".