1641663673 has 16 divisors (see below), whose sum is σ = 1788066000. Its totient is φ = 1498233600.

The previous prime is 1641663649. The next prime is 1641663689. The reversal of 1641663673 is 3763661461.

It can be written as a sum of positive squares in 8 ways, for example, as 66129424 + 1575534249 = 8132^2 + 39693^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641663673 - 2¹³ = 1641655481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1641663173) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 441723 + ... + 445423.

It is an arithmetic number, because the mean of its divisors is an integer number (111754125).

Almost surely, 2^1641663673 is an apocalyptic number.

1641663673 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

1641663673 is a deficient number, since it is larger than the sum of its proper divisors (146402327).

1641663673 is a wasteful number, since it uses less digits than its factorization.

1641663673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4092.

The product of its digits is 326592, while the sum is 43.

The square root of 1641663673 is about 40517.4489942296. The cubic root of 1641663673 is about 1179.6723386416.

It can be divided in two parts, 16416 and 63673, that added together give a square (80089 = 283²).

The spelling of 1641663673 in words is "one billion, six hundred forty-one million, six hundred sixty-three thousand, six hundred seventy-three".