42778 has 8 divisors (see below), whose sum is σ = 65268. Its totient is φ = 21024.

The previous prime is 42773. The next prime is 42787. The reversal of 42778 is 87724.

42778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

42778 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

42778 is a nontrivial binomial coefficient, being equal to C(293, 2).

It can be written as a sum of positive squares in 2 ways, for example, as 38809 + 3969 = 197^2 + 63^2 .

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

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, 1 + ... + 292.

2⁴²⁷⁷⁸ is an apocalyptic number.

42778 is the 292-nd triangular number.

42778 is the 98-th centered nonagonal number.

42778 is a deficient number, since it is larger than the sum of its proper divisors (22490).

42778 is a wasteful number, since it uses less digits than its factorization.

42778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368.

The product of its digits is 3136, while the sum is 28.

The square root of 42778 is about 206.8284313145. The cubic root of 42778 is about 34.9735855122.

It can be divided in two parts, 427 and 78, that added together give a palindrome (505).

The spelling of 42778 in words is "forty-two thousand, seven hundred seventy-eight".