42781234 has 4 divisors (see below), whose sum is σ = 64171854. Its totient is φ = 21390616.

The previous prime is 42781199. The next prime is 42781237. The reversal of 42781234 is 43218724.

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

It can be written as a sum of positive squares in only one way, i.e., 30858025 + 11923209 = 5555^2 + 3453^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 42781196 and 42781205.

It is not an unprimeable number, because it can be changed into a prime (42781237) 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 as a sum of consecutive naturals, namely, 10695307 + ... + 10695310.

Almost surely, 2^42781234 is an apocalyptic number.

42781234 is a deficient number, since it is larger than the sum of its proper divisors (21390620).

42781234 is a wasteful number, since it uses less digits than its factorization.

42781234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21390619.

The product of its digits is 10752, while the sum is 31.

The square root of 42781234 is about 6540.7365028718. The cubic root of 42781234 is about 349.7446681976.

Adding to 42781234 its reverse (43218724), we get a palindrome (85999958).

The spelling of 42781234 in words is "forty-two million, seven hundred eighty-one thousand, two hundred thirty-four".