201212861 has 2 divisors, whose sum is σ = 201212862. Its totient is φ = 201212860.

The previous prime is 201212849. The next prime is 201212863. The reversal of 201212861 is 168212102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197936761 + 3276100 = 14069^2 + 1810^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201212861 is a prime.

Together with 201212863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201212863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100606430 + 100606431.

It is an arithmetic number, because the mean of its divisors is an integer number (100606431).

Almost surely, 2^201212861 is an apocalyptic number.

It is an amenable number.

201212861 is a deficient number, since it is larger than the sum of its proper divisors (1).

201212861 is an equidigital number, since it uses as much as digits as its factorization.

201212861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 23.

The square root of 201212861 is about 14184.9519209619. The cubic root of 201212861 is about 585.9833083963.

Adding to 201212861 its reverse (168212102), we get a palindrome (369424963).

The spelling of 201212861 in words is "two hundred one million, two hundred twelve thousand, eight hundred sixty-one".