1649267441681 has 2 divisors, whose sum is σ = 1649267441682. Its totient is φ = 1649267441680.

The previous prime is 1649267441651. The next prime is 1649267441693. The reversal of 1649267441681 is 1861447629461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 904353450625 + 744913991056 = 950975^2 + 863084^2 .

It is a cyclic number.

It is not a de Polignac number, because 1649267441681 - 2⁶ = 1649267441617 is a prime.

It is a super-2 number, since 2×1649267441681² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1649267441681.

It is not a weakly prime, because it can be changed into another prime (1649267441611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 824633720840 + 824633720841.

It is an arithmetic number, because the mean of its divisors is an integer number (824633720841).

Almost surely, 2^{1649267441681} is an apocalyptic number.

It is an amenable number.

1649267441681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1649267441681 is an equidigital number, since it uses as much as digits as its factorization.

1649267441681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13934592, while the sum is 59.

The spelling of 1649267441681 in words is "one trillion, six hundred forty-nine billion, two hundred sixty-seven million, four hundred forty-one thousand, six hundred eighty-one".