61439 has 8 divisors (see below), whose sum is σ = 71808. Its totient is φ = 51480.

The previous prime is 61417. The next prime is 61441. The reversal of 61439 is 93416.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61439 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 8 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61409) 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, 404 + ... + 534.

It is an arithmetic number, because the mean of its divisors is an integer number (8976).

2⁶¹⁴³⁹ is an apocalyptic number.

61439 is a deficient number, since it is larger than the sum of its proper divisors (10369).

61439 is a wasteful number, since it uses less digits than its factorization.

61439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205.

The product of its digits is 648, while the sum is 23.

The square root of 61439 is about 247.8689169702. The cubic root of 61439 is about 39.4591791072.

Subtracting from 61439 its sum of digits (23), we obtain a palindrome (61416).

The spelling of 61439 in words is "sixty-one thousand, four hundred thirty-nine".