1644081406757 has 2 divisors, whose sum is σ = 1644081406758. Its totient is φ = 1644081406756.

The previous prime is 1644081406703. The next prime is 1644081406801. The reversal of 1644081406757 is 7576041804461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1601416851841 + 42664554916 = 1265471^2 + 206554^2 .

It is a cyclic number.

It is not a de Polignac number, because 1644081406757 - 2³⁰ = 1643007664933 is a prime.

It is a super-3 number, since 3×1644081406757³ (a number of 38 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1644081406699 and 1644081406708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1644081406157) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822040703378 + 822040703379.

It is an arithmetic number, because the mean of its divisors is an integer number (822040703379).

Almost surely, 2^{1644081406757} is an apocalyptic number.

It is an amenable number.

1644081406757 is a deficient number, since it is larger than the sum of its proper divisors (1).

1644081406757 is an equidigital number, since it uses as much as digits as its factorization.

1644081406757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4515840, while the sum is 53.

The spelling of 1644081406757 in words is "one trillion, six hundred forty-four billion, eighty-one million, four hundred six thousand, seven hundred fifty-seven".