212318261 has 8 divisors (see below), whose sum is σ = 215212248. Its totient is φ = 209440000.

The previous prime is 212318257. The next prime is 212318263. The reversal of 212318261 is 162813212.

It can be written as a sum of positive squares in 4 ways, for example, as 146870161 + 65448100 = 12119^2 + 8090^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212318261 - 2² = 212318257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212318261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212318263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24641 + ... + 32121.

It is an arithmetic number, because the mean of its divisors is an integer number (26901531).

Almost surely, 2^212318261 is an apocalyptic number.

It is an amenable number.

212318261 is a deficient number, since it is larger than the sum of its proper divisors (2893987).

212318261 is a wasteful number, since it uses less digits than its factorization.

212318261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7863.

The product of its digits is 1152, while the sum is 26.

The square root of 212318261 is about 14571.1448074611. The cubic root of 212318261 is about 596.5714278806.

It can be divided in two parts, 21231 and 8261, that added together give a palindrome (29492).

The spelling of 212318261 in words is "two hundred twelve million, three hundred eighteen thousand, two hundred sixty-one".