421440401 has 2 divisors, whose sum is σ = 421440402. Its totient is φ = 421440400.

The previous prime is 421440367. The next prime is 421440403. The reversal of 421440401 is 104044124.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 393982801 + 27457600 = 19849^2 + 5240^2 .

It is a cyclic number.

It is not a de Polignac number, because 421440401 - 2⁶ = 421440337 is a prime.

It is a super-2 number, since 2×421440401² = 355224023190081602, which contains 22 as substring.

Together with 421440403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (421440403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210720200 + 210720201.

It is an arithmetic number, because the mean of its divisors is an integer number (210720201).

Almost surely, 2^421440401 is an apocalyptic number.

It is an amenable number.

421440401 is a deficient number, since it is larger than the sum of its proper divisors (1).

421440401 is an equidigital number, since it uses as much as digits as its factorization.

421440401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 421440401 is about 20529.0136392375. The cubic root of 421440401 is about 749.7423713653.

Adding to 421440401 its reverse (104044124), we get a palindrome (525484525).

The spelling of 421440401 in words is "four hundred twenty-one million, four hundred forty thousand, four hundred one".