2191804236449 has 2 divisors, whose sum is σ = 2191804236450. Its totient is φ = 2191804236448.

The previous prime is 2191804236437. The next prime is 2191804236467. The reversal of 2191804236449 is 9446324081912.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1993088885824 + 198715350625 = 1411768^2 + 445775^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2191804236449 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2191804236449.

It is not a weakly prime, because it can be changed into another prime (2191804736449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095902118224 + 1095902118225.

It is an arithmetic number, because the mean of its divisors is an integer number (1095902118225).

Almost surely, 2^{2191804236449} is an apocalyptic number.

It is an amenable number.

2191804236449 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191804236449 is an equidigital number, since it uses as much as digits as its factorization.

2191804236449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2985984, while the sum is 53.

The spelling of 2191804236449 in words is "two trillion, one hundred ninety-one billion, eight hundred four million, two hundred thirty-six thousand, four hundred forty-nine".