42406121 has 2 divisors, whose sum is σ = 42406122. Its totient is φ = 42406120.

The previous prime is 42406103. The next prime is 42406129. The reversal of 42406121 is 12160424.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21576025 + 20830096 = 4645^2 + 4564^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42406121 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 42406093 and 42406102.

It is not a weakly prime, because it can be changed into another prime (42406129) 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, 21203060 + 21203061.

It is an arithmetic number, because the mean of its divisors is an integer number (21203061).

Almost surely, 2^42406121 is an apocalyptic number.

It is an amenable number.

42406121 is a deficient number, since it is larger than the sum of its proper divisors (1).

42406121 is an equidigital number, since it uses as much as digits as its factorization.

42406121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 42406121 is about 6511.9982340292. The cubic root of 42406121 is about 348.7194593914.

Adding to 42406121 its reverse (12160424), we get a palindrome (54566545).

The spelling of 42406121 in words is "forty-two million, four hundred six thousand, one hundred twenty-one".