42879281 has 2 divisors, whose sum is σ = 42879282. Its totient is φ = 42879280.

The previous prime is 42879233. The next prime is 42879283. The reversal of 42879281 is 18297824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42706225 + 173056 = 6535^2 + 416^2 .

It is a cyclic number.

It is not a de Polignac number, because 42879281 - 2²² = 38684977 is a prime.

It is a super-2 number, since 2×42879281² = 3677265478153922, which contains 22 as substring.

Together with 42879283, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_2597729 and since 42879281 and 2597729 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (42879283) 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, 21439640 + 21439641.

It is an arithmetic number, because the mean of its divisors is an integer number (21439641).

Almost surely, 2^42879281 is an apocalyptic number.

It is an amenable number.

42879281 is a deficient number, since it is larger than the sum of its proper divisors (1).

42879281 is an equidigital number, since it uses as much as digits as its factorization.

42879281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64512, while the sum is 41.

The square root of 42879281 is about 6548.2273173738. The cubic root of 42879281 is about 350.0116485919.

The spelling of 42879281 in words is "forty-two million, eight hundred seventy-nine thousand, two hundred eighty-one".