213212261 has 2 divisors, whose sum is σ = 213212262. Its totient is φ = 213212260.

The previous prime is 213212179. The next prime is 213212267. The reversal of 213212261 is 162212312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209236225 + 3976036 = 14465^2 + 1994^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213212261 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213212267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106606130 + 106606131.

It is an arithmetic number, because the mean of its divisors is an integer number (106606131).

Almost surely, 2^213212261 is an apocalyptic number.

It is an amenable number.

213212261 is a deficient number, since it is larger than the sum of its proper divisors (1).

213212261 is an equidigital number, since it uses as much as digits as its factorization.

213212261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 288, while the sum is 20.

The square root of 213212261 is about 14601.7896505874. The cubic root of 213212261 is about 597.4075752069.

Adding to 213212261 its reverse (162212312), we get a palindrome (375424573).

The spelling of 213212261 in words is "two hundred thirteen million, two hundred twelve thousand, two hundred sixty-one".