212131261 has 2 divisors, whose sum is σ = 212131262. Its totient is φ = 212131260.

The previous prime is 212131247. The next prime is 212131279. The reversal of 212131261 is 162131212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 145202500 + 66928761 = 12050^2 + 8181^2 .

It is a cyclic number.

It is not a de Polignac number, because 212131261 - 2⁵ = 212131229 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212131861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106065630 + 106065631.

It is an arithmetic number, because the mean of its divisors is an integer number (106065631).

Almost surely, 2^212131261 is an apocalyptic number.

It is an amenable number.

212131261 is a deficient number, since it is larger than the sum of its proper divisors (1).

212131261 is an equidigital number, since it uses as much as digits as its factorization.

212131261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 19.

The square root of 212131261 is about 14564.7266023087. The cubic root of 212131261 is about 596.3962323597.

Adding to 212131261 its reverse (162131212), we get a palindrome (374262473).

The spelling of 212131261 in words is "two hundred twelve million, one hundred thirty-one thousand, two hundred sixty-one".