421204021 has 8 divisors (see below), whose sum is σ = 488156544. Its totient is φ = 355946640.

The previous prime is 421203983. The next prime is 421204031. The reversal of 421204021 is 120402124.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 421204021 - 2¹⁹ = 420679733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421203986 and 421204004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421204031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 423250 + ... + 424243.

It is an arithmetic number, because the mean of its divisors is an integer number (61019568).

Almost surely, 2^421204021 is an apocalyptic number.

It is an amenable number.

421204021 is a deficient number, since it is larger than the sum of its proper divisors (66952523).

421204021 is an equidigital number, since it uses as much as digits as its factorization.

421204021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847571.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 421204021 is about 20523.2556140589. The cubic root of 421204021 is about 749.6021718291.

Adding to 421204021 its reverse (120402124), we get a palindrome (541606145).

The spelling of 421204021 in words is "four hundred twenty-one million, two hundred four thousand, twenty-one".