673737021 has 10 divisors (see below), whose sum is σ = 1006446782. Its totient is φ = 449157960.

The previous prime is 673737011. The next prime is 673737023. The reversal of 673737021 is 120737376.

It can be written as a sum of positive squares in only one way, i.e., 417384900 + 256352121 = 20430^2 + 16011^2 .

It is not a de Polignac number, because 673737021 - 2¹³ = 673728829 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 (673737023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 4158790 + ... + 4158951.

Almost surely, 2^673737021 is an apocalyptic number.

It is an amenable number.

673737021 is a deficient number, since it is larger than the sum of its proper divisors (332709761).

673737021 is an equidigital number, since it uses as much as digits as its factorization.

673737021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8317753 (or 8317744 counting only the distinct ones).

The product of its (nonzero) digits is 37044, while the sum is 36.

The square root of 673737021 is about 25956.4446910589. Note that the first 3 decimals coincide. The cubic root of 673737021 is about 876.6578727707.

The spelling of 673737021 in words is "six hundred seventy-three million, seven hundred thirty-seven thousand, twenty-one".