421325021 has 24 divisors (see below), whose sum is σ = 476297640. Its totient is φ = 370427904.

The previous prime is 421324997. The next prime is 421325027. The reversal of 421325021 is 120523124.

It can be written as a sum of positive squares in 12 ways, for example, as 279357796 + 141967225 = 16714^2 + 11915^2 .

It is not a de Polignac number, because 421325021 - 2¹⁰ = 421323997 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 421324984 and 421325002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421325027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 972821 + ... + 973253.

It is an arithmetic number, because the mean of its divisors is an integer number (19845735).

Almost surely, 2^421325021 is an apocalyptic number.

It is an amenable number.

421325021 is a deficient number, since it is larger than the sum of its proper divisors (54972619).

421325021 is a wasteful number, since it uses less digits than its factorization.

421325021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 421325021 is about 20526.2032777618. The cubic root of 421325021 is about 749.6739447897.

Adding to 421325021 its reverse (120523124), we get a palindrome (541848145).

The spelling of 421325021 in words is "four hundred twenty-one million, three hundred twenty-five thousand, twenty-one".