213421605 has 32 divisors (see below), whose sum is σ = 352114560. Its totient is φ = 110315520.

The previous prime is 213421603. The next prime is 213421609. The reversal of 213421605 is 506124312.

It is not a de Polignac number, because 213421605 - 2¹ = 213421603 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213421601) 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 31 ways as a sum of consecutive naturals, for example, 99181 + ... + 101309.

It is an arithmetic number, because the mean of its divisors is an integer number (11003580).

Almost surely, 2^213421605 is an apocalyptic number.

It is an amenable number.

213421605 is a deficient number, since it is larger than the sum of its proper divisors (138692955).

213421605 is a wasteful number, since it uses less digits than its factorization.

213421605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2341.

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 213421605 is about 14608.9563282255. The cubic root of 213421605 is about 597.6030342322.

Adding to 213421605 its reverse (506124312), we get a palindrome (719545917).

The spelling of 213421605 in words is "two hundred thirteen million, four hundred twenty-one thousand, six hundred five".