61709 has 4 divisors (see below), whose sum is σ = 64416. Its totient is φ = 59004.

The previous prime is 61703. The next prime is 61717. The reversal of 61709 is 90716.

It is a happy number.

61709 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61709 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 2683 = 61709 / (6 + 1 + 7 + 0 + 9).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1319 + ... + 1364.

It is an arithmetic number, because the mean of its divisors is an integer number (16104).

2⁶¹⁷⁰⁹ is an apocalyptic number.

It is an amenable number.

61709 is a deficient number, since it is larger than the sum of its proper divisors (2707).

61709 is a wasteful number, since it uses less digits than its factorization.

61709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2706.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 61709 is about 248.4129626247. The cubic root of 61709 is about 39.5168971131.

The spelling of 61709 in words is "sixty-one thousand, seven hundred nine".