213212605 has 4 divisors (see below), whose sum is σ = 255855132. Its totient is φ = 170570080.

The previous prime is 213212579. The next prime is 213212609. The reversal of 213212605 is 506212312.

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 47858724 + 165353881 = 6918^2 + 12859^2 .

It is not a de Polignac number, because 213212605 - 2¹³ = 213204413 is a prime.

It is a super-3 number, since 3×213212605³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213212609) 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, 21321256 + ... + 21321265.

It is an arithmetic number, because the mean of its divisors is an integer number (63963783).

Almost surely, 2^213212605 is an apocalyptic number.

It is an amenable number.

213212605 is a deficient number, since it is larger than the sum of its proper divisors (42642527).

213212605 is an equidigital number, since it uses as much as digits as its factorization.

213212605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42642526.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 213212605 is about 14601.8014299606. The cubic root of 213212605 is about 597.4078964957.

Adding to 213212605 its reverse (506212312), we get a palindrome (719424917).

The spelling of 213212605 in words is "two hundred thirteen million, two hundred twelve thousand, six hundred five".