421793621 has 4 divisors (see below), whose sum is σ = 423544044. Its totient is φ = 420043200.

The previous prime is 421793591. The next prime is 421793623. The reversal of 421793621 is 126397124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 224700100 + 197093521 = 14990^2 + 14039^2 .

It is a cyclic number.

It is not a de Polignac number, because 421793621 - 2¹⁰ = 421792597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (421793623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 874850 + ... + 875331.

It is an arithmetic number, because the mean of its divisors is an integer number (105886011).

Almost surely, 2^421793621 is an apocalyptic number.

It is an amenable number.

421793621 is a deficient number, since it is larger than the sum of its proper divisors (1750423).

421793621 is a wasteful number, since it uses less digits than its factorization.

421793621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1750422.

The product of its digits is 18144, while the sum is 35.

The square root of 421793621 is about 20537.6147836111. The cubic root of 421793621 is about 749.9517723063.

The spelling of 421793621 in words is "four hundred twenty-one million, seven hundred ninety-three thousand, six hundred twenty-one".