1212965800649 has 4 divisors (see below), whose sum is σ = 1245748660164. Its totient is φ = 1180182941136.

The previous prime is 1212965800621. The next prime is 1212965800663. The reversal of 1212965800649 is 9460085692121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 575235784249 + 637730016400 = 758443^2 + 798580^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1212965800649 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 1212965800649.

It is not an unprimeable number, because it can be changed into a prime (1212965802649) 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 in 3 ways as a sum of consecutive naturals, for example, 16391429702 + ... + 16391429775.

It is an arithmetic number, because the mean of its divisors is an integer number (311437165041).

Almost surely, 2^{1212965800649} is an apocalyptic number.

It is an amenable number.

1212965800649 is a deficient number, since it is larger than the sum of its proper divisors (32782859515).

1212965800649 is an equidigital number, since it uses as much as digits as its factorization.

1212965800649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32782859514.

The product of its (nonzero) digits is 1866240, while the sum is 53.

The spelling of 1212965800649 in words is "one trillion, two hundred twelve billion, nine hundred sixty-five million, eight hundred thousand, six hundred forty-nine".