1644081967499 has 2 divisors, whose sum is σ = 1644081967500. Its totient is φ = 1644081967498.

The previous prime is 1644081967427. The next prime is 1644081967529. The reversal of 1644081967499 is 9947691804461.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1644081967499 - 2⁸ = 1644081967243 is a prime.

It is a super-3 number, since 3×1644081967499³ (a number of 38 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (1644081967999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822040983749 + 822040983750.

It is an arithmetic number, because the mean of its divisors is an integer number (822040983750).

Almost surely, 2^{1644081967499} is an apocalyptic number.

1644081967499 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644081967499 is an equidigital number, since it uses as much as digits as its factorization.

1644081967499 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 94058496, while the sum is 68.

The spelling of 1644081967499 in words is "one trillion, six hundred forty-four billion, eighty-one million, nine hundred sixty-seven thousand, four hundred ninety-nine".