421006393 has 4 divisors (see below), whose sum is σ = 421217140. Its totient is φ = 420795648.

The previous prime is 421006367. The next prime is 421006429. The reversal of 421006393 is 393600124.

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 333172009 + 87834384 = 18253^2 + 9372^2 .

It is a cyclic number.

It is not a de Polignac number, because 421006393 - 2⁹ = 421005881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (421004393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102348 + ... + 106381.

It is an arithmetic number, because the mean of its divisors is an integer number (105304285).

Almost surely, 2^421006393 is an apocalyptic number.

It is an amenable number.

421006393 is a deficient number, since it is larger than the sum of its proper divisors (210747).

421006393 is a wasteful number, since it uses less digits than its factorization.

421006393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210746.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 421006393 is about 20518.4403159694. The cubic root of 421006393 is about 749.4849162586.

The spelling of 421006393 in words is "four hundred twenty-one million, six thousand, three hundred ninety-three".