421233021 has 64 divisors (see below), whose sum is σ = 758937600. Its totient is φ = 227577600.

The previous prime is 421233019. The next prime is 421233047. The reversal of 421233021 is 120332124.

It is not a de Polignac number, because 421233021 - 2¹ = 421233019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 421232985 and 421233003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421233061) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 93736 + ... + 98126.

It is an arithmetic number, because the mean of its divisors is an integer number (11858400).

Almost surely, 2^421233021 is an apocalyptic number.

It is an amenable number.

421233021 is a deficient number, since it is larger than the sum of its proper divisors (337704579).

421233021 is a wasteful number, since it uses less digits than its factorization.

421233021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4447 (or 4441 counting only the distinct ones).

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

The square root of 421233021 is about 20523.9621174860. The cubic root of 421233021 is about 749.6193748654.

Adding to 421233021 its reverse (120332124), we get a palindrome (541565145).

The spelling of 421233021 in words is "four hundred twenty-one million, two hundred thirty-three thousand, twenty-one".