61749 has 8 divisors (see below), whose sum is σ = 91520. Its totient is φ = 41148.

The previous prime is 61729. The next prime is 61751. The reversal of 61749 is 94716.

61749 is a `hidden beast` number, since 617 + 49 = 666.

It is not a de Polignac number, because 61749 - 2⁵ = 61717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 2287 = 61749 / (6 + 1 + 7 + 4 + 9).

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1117 + ... + 1170.

It is an arithmetic number, because the mean of its divisors is an integer number (11440).

2⁶¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

61749 is a deficient number, since it is larger than the sum of its proper divisors (29771).

61749 is a wasteful number, since it uses less digits than its factorization.

61749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2296 (or 2290 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 61749 is about 248.4934606785. The cubic root of 61749 is about 39.5254336014.

Adding to 61749 its sum of digits (27), we get a triangular number (61776 = T₃₅₁).

It can be divided in two parts, 617 and 49, that added together give a palindrome (666).

The spelling of 61749 in words is "sixty-one thousand, seven hundred forty-nine".