213404305 has 4 divisors (see below), whose sum is σ = 256085172. Its totient is φ = 170723440.

The previous prime is 213404297. The next prime is 213404309. The reversal of 213404305 is 503404312.

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 22052416 + 191351889 = 4696^2 + 13833^2 .

It is not a de Polignac number, because 213404305 - 2³ = 213404297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (213404309) 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, 21340426 + ... + 21340435.

It is an arithmetic number, because the mean of its divisors is an integer number (64021293).

Almost surely, 2^213404305 is an apocalyptic number.

It is an amenable number.

213404305 is a deficient number, since it is larger than the sum of its proper divisors (42680867).

213404305 is an equidigital number, since it uses as much as digits as its factorization.

213404305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42680866.

The product of its (nonzero) digits is 1440, while the sum is 22.

The square root of 213404305 is about 14608.3642136962. The cubic root of 213404305 is about 597.5868865202.

Adding to 213404305 its reverse (503404312), we get a palindrome (716808617).

The spelling of 213404305 in words is "two hundred thirteen million, four hundred four thousand, three hundred five".