1212844861 has 2 divisors, whose sum is σ = 1212844862. Its totient is φ = 1212844860.

The previous prime is 1212844859. The next prime is 1212844907. The reversal of 1212844861 is 1684482121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 954439236 + 258405625 = 30894^2 + 16075^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212844861 - 2¹ = 1212844859 is a prime.

Together with 1212844859, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1212844861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212844561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606422430 + 606422431.

It is an arithmetic number, because the mean of its divisors is an integer number (606422431).

Almost surely, 2^1212844861 is an apocalyptic number.

It is an amenable number.

1212844861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212844861 is an equidigital number, since it uses as much as digits as its factorization.

1212844861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24576, while the sum is 37.

The square root of 1212844861 is about 34825.9222562734. The cubic root of 1212844861 is about 1066.4367044083.

The spelling of 1212844861 in words is "one billion, two hundred twelve million, eight hundred forty-four thousand, eight hundred sixty-one".