61779 has 4 divisors (see below), whose sum is σ = 82376. Its totient is φ = 41184.

The previous prime is 61757. The next prime is 61781. The reversal of 61779 is 97716.

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

It is not a de Polignac number, because 61779 - 2⁷ = 61651 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is a plaindrome in base 15.

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 3 ways as a sum of consecutive naturals, for example, 10294 + ... + 10299.

It is an arithmetic number, because the mean of its divisors is an integer number (20594).

2⁶¹⁷⁷⁹ is an apocalyptic number.

61779 is a deficient number, since it is larger than the sum of its proper divisors (20597).

61779 is a wasteful number, since it uses less digits than its factorization.

61779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20596.

The product of its digits is 2646, while the sum is 30.

The square root of 61779 is about 248.5538171101. The cubic root of 61779 is about 39.5318335486.

Subtracting 61779 from its reverse (97716), we obtain a cube (35937 = 33³).

It can be divided in two parts, 617 and 79, that added together give a palindrome (696).

The spelling of 61779 in words is "sixty-one thousand, seven hundred seventy-nine".