42779 has 4 divisors (see below), whose sum is σ = 46680. Its totient is φ = 38880.

The previous prime is 42773. The next prime is 42787. The reversal of 42779 is 97724.

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-42779 is a prime.

It is a pancake number, because a pancake can be divided into 42779 parts by 292 straight cuts.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42773) 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, 1934 + ... + 1955.

It is an arithmetic number, because the mean of its divisors is an integer number (11670).

2⁴²⁷⁷⁹ is an apocalyptic number.

42779 is a deficient number, since it is larger than the sum of its proper divisors (3901).

42779 is a wasteful number, since it uses less digits than its factorization.

42779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3900.

The product of its digits is 3528, while the sum is 29.

The square root of 42779 is about 206.8308487629. The cubic root of 42779 is about 34.9738580301.

Subtracting 42779 from its reverse (97724), we obtain a palindrome (54945).

It can be divided in two parts, 427 and 79, that multiplied together give a palindrome (33733).

The spelling of 42779 in words is "forty-two thousand, seven hundred seventy-nine".