1673445661 has 4 divisors (see below), whose sum is σ = 1746204192. Its totient is φ = 1600687132.

The previous prime is 1673445623. The next prime is 1673445673. The reversal of 1673445661 is 1665443761.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1673445661 - 2⁹ = 1673445149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1673445601) 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 3 ways as a sum of consecutive naturals, for example, 36379231 + ... + 36379276.

It is an arithmetic number, because the mean of its divisors is an integer number (436551048).

Almost surely, 2^1673445661 is an apocalyptic number.

It is an amenable number.

1673445661 is a deficient number, since it is larger than the sum of its proper divisors (72758531).

1673445661 is an equidigital number, since it uses as much as digits as its factorization.

1673445661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72758530.

The product of its digits is 362880, while the sum is 43.

The square root of 1673445661 is about 40907.7701787814. The cubic root of 1673445661 is about 1187.2364042959.

The spelling of 1673445661 in words is "one billion, six hundred seventy-three million, four hundred forty-five thousand, six hundred sixty-one".