673444021 has 2 divisors, whose sum is σ = 673444022. Its totient is φ = 673444020.

The previous prime is 673443959. The next prime is 673444073. The reversal of 673444021 is 120444376.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 431019121 + 242424900 = 20761^2 + 15570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-673444021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (673444081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336722010 + 336722011.

It is an arithmetic number, because the mean of its divisors is an integer number (336722011).

Almost surely, 2^673444021 is an apocalyptic number.

It is an amenable number.

673444021 is a deficient number, since it is larger than the sum of its proper divisors (1).

673444021 is an equidigital number, since it uses as much as digits as its factorization.

673444021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16128, while the sum is 31.

The square root of 673444021 is about 25950.8000069362. The cubic root of 673444021 is about 876.5307717442.

Adding to 673444021 its reverse (120444376), we get a palindrome (793888397).

The spelling of 673444021 in words is "six hundred seventy-three million, four hundred forty-four thousand, twenty-one".