1664144361205 has 4 divisors (see below), whose sum is σ = 1996973233452. Its totient is φ = 1331315488960.

The previous prime is 1664144361109. The next prime is 1664144361223. The reversal of 1664144361205 is 5021634414661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 484361713521 + 1179782647684 = 695961^2 + 1086178^2 .

It is not a de Polignac number, because 1664144361205 - 2¹⁹ = 1664143836917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166414436116 + ... + 166414436125.

It is an arithmetic number, because the mean of its divisors is an integer number (499243308363).

Almost surely, 2^{1664144361205} is an apocalyptic number.

It is an amenable number.

1664144361205 is a deficient number, since it is larger than the sum of its proper divisors (332828872247).

1664144361205 is an equidigital number, since it uses as much as digits as its factorization.

1664144361205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 332828872246.

The product of its (nonzero) digits is 414720, while the sum is 43.

Adding to 1664144361205 its reverse (5021634414661), we get a palindrome (6685778775866).

The spelling of 1664144361205 in words is "one trillion, six hundred sixty-four billion, one hundred forty-four million, three hundred sixty-one thousand, two hundred five".