421040421 has 12 divisors (see below), whose sum is σ = 616501548. Its totient is φ = 276848064.

The previous prime is 421040407. The next prime is 421040441. The reversal of 421040421 is 124040124.

It can be written as a sum of positive squares in 2 ways, for example, as 229522500 + 191517921 = 15150^2 + 13839^2 .

It is not a de Polignac number, because 421040421 - 2⁷ = 421040293 is a prime.

It is a super-2 number, since 2×421040421² = 354550072231714482, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 421040394 and 421040403.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421040441) 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 in 11 ways as a sum of consecutive naturals, for example, 319770 + ... + 321083.

It is an arithmetic number, because the mean of its divisors is an integer number (51375129).

Almost surely, 2^421040421 is an apocalyptic number.

It is an amenable number.

421040421 is a deficient number, since it is larger than the sum of its proper divisors (195461127).

421040421 is a wasteful number, since it uses less digits than its factorization.

421040421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640932 (or 640929 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 421040421 is about 20519.2695045413. The cubic root of 421040421 is about 749.5051081813.

Adding to 421040421 its reverse (124040124), we get a palindrome (545080545).

The spelling of 421040421 in words is "four hundred twenty-one million, forty thousand, four hundred twenty-one".