1643645201326 has 16 divisors (see below), whose sum is σ = 2545037821440. Its totient is φ = 795300069240.

The previous prime is 1643645201269. The next prime is 1643645201327. The reversal of 1643645201326 is 6231025463461.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643645201327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4947105 + ... + 5268883.

It is an arithmetic number, because the mean of its divisors is an integer number (159064863840).

Almost surely, 2^{1643645201326} is an apocalyptic number.

1643645201326 is a deficient number, since it is larger than the sum of its proper divisors (901392620114).

1643645201326 is a wasteful number, since it uses less digits than its factorization.

1643645201326 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404199.

The product of its (nonzero) digits is 622080, while the sum is 43.

The spelling of 1643645201326 in words is "one trillion, six hundred forty-three billion, six hundred forty-five million, two hundred one thousand, three hundred twenty-six".