421323021 has 24 divisors (see below), whose sum is σ = 709716800. Its totient is φ = 240754248.

The previous prime is 421322983. The next prime is 421323029. The reversal of 421323021 is 120323124.

It is not a de Polignac number, because 421323021 - 2¹¹ = 421320973 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421322985 and 421323003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421323029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 65155 + ... + 71328.

Almost surely, 2^421323021 is an apocalyptic number.

It is an amenable number.

421323021 is a deficient number, since it is larger than the sum of its proper divisors (288393779).

421323021 is a wasteful number, since it uses less digits than its factorization.

421323021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136510 (or 136493 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 421323021 is about 20526.1545594882. The cubic root of 421323021 is about 749.6727585715.

Adding to 421323021 its reverse (120323124), we get a palindrome (541646145).

The spelling of 421323021 in words is "four hundred twenty-one million, three hundred twenty-three thousand, twenty-one".