42420401 has 2 divisors, whose sum is σ = 42420402. Its totient is φ = 42420400.

The previous prime is 42420379. The next prime is 42420419. The reversal of 42420401 is 10402424.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29170801 + 13249600 = 5401^2 + 3640^2 .

It is a cyclic number.

It is not a de Polignac number, because 42420401 - 2¹⁴ = 42404017 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 42420401.

It is not a weakly prime, because it can be changed into another prime (42420451) 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, 21210200 + 21210201.

It is an arithmetic number, because the mean of its divisors is an integer number (21210201).

Almost surely, 2^42420401 is an apocalyptic number.

It is an amenable number.

42420401 is a deficient number, since it is larger than the sum of its proper divisors (1).

42420401 is an equidigital number, since it uses as much as digits as its factorization.

42420401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 42420401 is about 6513.0945793839. The cubic root of 42420401 is about 348.7585980417.

Adding to 42420401 its reverse (10402424), we get a palindrome (52822825).

The spelling of 42420401 in words is "forty-two million, four hundred twenty thousand, four hundred one".