213540305 has 16 divisors (see below), whose sum is σ = 279923904. Its totient is φ = 155090880.

The previous prime is 213540287. The next prime is 213540337. The reversal of 213540305 is 503045312.

It is not a de Polignac number, because 213540305 - 2¹⁰ = 213539281 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46367 + ... + 50763.

It is an arithmetic number, because the mean of its divisors is an integer number (17495244).

Almost surely, 2^213540305 is an apocalyptic number.

It is an amenable number.

213540305 is a deficient number, since it is larger than the sum of its proper divisors (66383599).

213540305 is a wasteful number, since it uses less digits than its factorization.

213540305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5296.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 213540305 is about 14613.0183398229. The cubic root of 213540305 is about 597.7138045443.

Adding to 213540305 its reverse (503045312), we get a palindrome (716585617).

The spelling of 213540305 in words is "two hundred thirteen million, five hundred forty thousand, three hundred five".