17644344649 has 2 divisors, whose sum is σ = 17644344650. Its totient is φ = 17644344648.

The previous prime is 17644344647. The next prime is 17644344667. The reversal of 17644344649 is 94644344671.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13336785225 + 4307559424 = 115485^2 + 65632^2 .

It is a cyclic number.

It is not a de Polignac number, because 17644344649 - 2¹ = 17644344647 is a prime.

It is a super-2 number, since 2×17644344649² (a number of 21 digits) contains 22 as substring.

Together with 17644344647, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 17644344596 and 17644344605.

It is not a weakly prime, because it can be changed into another prime (17644344647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8822172324 + 8822172325.

It is an arithmetic number, because the mean of its divisors is an integer number (8822172325).

Almost surely, 2^17644344649 is an apocalyptic number.

It is an amenable number.

17644344649 is a deficient number, since it is larger than the sum of its proper divisors (1).

17644344649 is an equidigital number, since it uses as much as digits as its factorization.

17644344649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6967296, while the sum is 52.

The spelling of 17644344649 in words is "seventeen billion, six hundred forty-four million, three hundred forty-four thousand, six hundred forty-nine".