42781121 has 4 divisors (see below), whose sum is σ = 43383744. Its totient is φ = 42178500.

The previous prime is 42781099. The next prime is 42781159. The reversal of 42781121 is 12118724.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42781121 is a prime.

It is a Duffinian number.

It is a zygodrome in base 3.

It is not an unprimeable number, because it can be changed into a prime (42781181) 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 in 3 ways as a sum of consecutive naturals, for example, 301205 + ... + 301346.

It is an arithmetic number, because the mean of its divisors is an integer number (10845936).

Almost surely, 2^42781121 is an apocalyptic number.

It is an amenable number.

42781121 is a deficient number, since it is larger than the sum of its proper divisors (602623).

42781121 is an equidigital number, since it uses as much as digits as its factorization.

42781121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602622.

The product of its digits is 896, while the sum is 26.

The square root of 42781121 is about 6540.7278646952. The cubic root of 42781121 is about 349.7443602652.

Adding to 42781121 its reverse (12118724), we get a palindrome (54899845).

The spelling of 42781121 in words is "forty-two million, seven hundred eighty-one thousand, one hundred twenty-one".