421313021 has 4 divisors (see below), whose sum is σ = 421981344. Its totient is φ = 420644700.

The previous prime is 421312999. The next prime is 421313051. The reversal of 421313021 is 120313124.

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 421313021 - 2¹⁰ = 421311997 is a prime.

It is a super-3 number, since 3×421313021³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421313051) 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, 333215 + ... + 334476.

It is an arithmetic number, because the mean of its divisors is an integer number (105495336).

Almost surely, 2^421313021 is an apocalyptic number.

It is an amenable number.

421313021 is a deficient number, since it is larger than the sum of its proper divisors (668323).

421313021 is an equidigital number, since it uses as much as digits as its factorization.

421313021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668322.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 421313021 is about 20525.9109663859. The cubic root of 421313021 is about 749.6668274240. Note that the first 3 decimals are identical.

Adding to 421313021 its reverse (120313124), we get a palindrome (541626145).

The spelling of 421313021 in words is "four hundred twenty-one million, three hundred thirteen thousand, twenty-one".