673921 has 2 divisors, whose sum is σ = 673922. Its totient is φ = 673920.

The previous prime is 673891. The next prime is 673943. The reversal of 673921 is 129376.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 672400 + 1521 = 820^2 + 39^2 .

It is a cyclic number.

It is not a de Polignac number, because 673921 - 2⁷ = 673793 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 673921.

It is not a weakly prime, because it can be changed into another prime (673951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336960 + 336961.

It is an arithmetic number, because the mean of its divisors is an integer number (336961).

2⁶⁷³⁹²¹ is an apocalyptic number.

It is an amenable number.

673921 is a deficient number, since it is larger than the sum of its proper divisors (1).

673921 is an equidigital number, since it uses as much as digits as its factorization.

673921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2268, while the sum is 28.

The square root of 673921 is about 820.9269151392. The cubic root of 673921 is about 87.6737662538.

The spelling of 673921 in words is "six hundred seventy-three thousand, nine hundred twenty-one".