42490421 has 2 divisors, whose sum is σ = 42490422. Its totient is φ = 42490420.

The previous prime is 42490417. The next prime is 42490477. The reversal of 42490421 is 12409424.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36663025 + 5827396 = 6055^2 + 2414^2 .

It is a cyclic number.

It is not a de Polignac number, because 42490421 - 2² = 42490417 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42490121) 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, 21245210 + 21245211.

It is an arithmetic number, because the mean of its divisors is an integer number (21245211).

Almost surely, 2^42490421 is an apocalyptic number.

It is an amenable number.

42490421 is a deficient number, since it is larger than the sum of its proper divisors (1).

42490421 is an equidigital number, since it uses as much as digits as its factorization.

42490421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 42490421 is about 6518.4676880383. The cubic root of 42490421 is about 348.9503819686.

Adding to 42490421 its reverse (12409424), we get a palindrome (54899845).

The spelling of 42490421 in words is "forty-two million, four hundred ninety thousand, four hundred twenty-one".