421121021 has 4 divisors (see below), whose sum is σ = 421176000. Its totient is φ = 421066044.

The previous prime is 421121017. The next prime is 421121047. The reversal of 421121021 is 120121124.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 421121021 - 2² = 421121017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 421120987 and 421121005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421121011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13691 + ... + 32088.

It is an arithmetic number, because the mean of its divisors is an integer number (105294000).

Almost surely, 2^421121021 is an apocalyptic number.

It is an amenable number.

421121021 is a deficient number, since it is larger than the sum of its proper divisors (54979).

421121021 is an equidigital number, since it uses as much as digits as its factorization.

421121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54978.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 421121021 is about 20521.2334180965. The cubic root of 421121021 is about 749.5529311886.

Adding to 421121021 its reverse (120121124), we get a palindrome (541242145).

The spelling of 421121021 in words is "four hundred twenty-one million, one hundred twenty-one thousand, twenty-one".