61139 has 4 divisors (see below), whose sum is σ = 65856. Its totient is φ = 56424.

The previous prime is 61129. The next prime is 61141. The reversal of 61139 is 93116.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61139 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 61139.

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, 2339 + ... + 2364.

It is an arithmetic number, because the mean of its divisors is an integer number (16464).

2⁶¹¹³⁹ is an apocalyptic number.

61139 is a deficient number, since it is larger than the sum of its proper divisors (4717).

61139 is a wasteful number, since it uses less digits than its factorization.

61139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4716.

The product of its digits is 162, while the sum is 20.

The square root of 61139 is about 247.2630178575. The cubic root of 61139 is about 39.3948493185.

The spelling of 61139 in words is "sixty-one thousand, one hundred thirty-nine".