1646991582989 has 2 divisors, whose sum is σ = 1646991582990. Its totient is φ = 1646991582988.

The previous prime is 1646991582983. The next prime is 1646991583019. The reversal of 1646991582989 is 9892851996461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1595883938089 + 51107644900 = 1263283^2 + 226070^2 .

It is a cyclic number.

It is not a de Polignac number, because 1646991582989 - 2¹⁶ = 1646991517453 is a prime.

It is a super-2 number, since 2×1646991582989² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1646991582983) 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, 823495791494 + 823495791495.

It is an arithmetic number, because the mean of its divisors is an integer number (823495791495).

Almost surely, 2^{1646991582989} is an apocalyptic number.

It is an amenable number.

1646991582989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1646991582989 is an equidigital number, since it uses as much as digits as its factorization.

1646991582989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 604661760, while the sum is 77.

The spelling of 1646991582989 in words is "one trillion, six hundred forty-six billion, nine hundred ninety-one million, five hundred eighty-two thousand, nine hundred eighty-nine".