61785 has 12 divisors (see below), whose sum is σ = 107172. Its totient is φ = 32928.

The previous prime is 61781. The next prime is 61813. The reversal of 61785 is 58716.

It can be written as a sum of positive squares in 2 ways, for example, as 46656 + 15129 = 216^2 + 123^2 .

It is not a de Polignac number, because 61785 - 2² = 61781 is a prime.

61785 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 61785.

It is not an unprimeable number, because it can be changed into a prime (61781) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 642 + ... + 731.

It is an arithmetic number, because the mean of its divisors is an integer number (8931).

2⁶¹⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

61785 is a deficient number, since it is larger than the sum of its proper divisors (45387).

61785 is a wasteful number, since it uses less digits than its factorization.

61785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1384 (or 1381 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 61785 is about 248.5658866377. The cubic root of 61785 is about 39.5331132895.

The spelling of 61785 in words is "sixty-one thousand, seven hundred eighty-five".