61109 has 4 divisors (see below), whose sum is σ = 62316. Its totient is φ = 59904.

The previous prime is 61099. The next prime is 61121. The reversal of 61109 is 90116.

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 46225 + 14884 = 215^2 + 122^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61109 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 524 + ... + 629.

It is an arithmetic number, because the mean of its divisors is an integer number (15579).

2⁶¹¹⁰⁹ is an apocalyptic number.

It is an amenable number.

61109 is a deficient number, since it is larger than the sum of its proper divisors (1207).

61109 is a wasteful number, since it uses less digits than its factorization.

61109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1206.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 61109 is about 247.2023462672. The cubic root of 61109 is about 39.3884047750.

The spelling of 61109 in words is "sixty-one thousand, one hundred nine".