673432421 has 4 divisors (see below), whose sum is σ = 689857644. Its totient is φ = 657007200.

The previous prime is 673432399. The next prime is 673432439. The reversal of 673432421 is 124234376.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 233020225 + 440412196 = 15265^2 + 20986^2 .

It is a cyclic number.

It is not a de Polignac number, because 673432421 - 2¹⁰ = 673431397 is a prime.

It is a super-2 number, since 2×673432421² = 907022451307842482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (673432481) 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 3 ways as a sum of consecutive naturals, for example, 8212550 + ... + 8212631.

It is an arithmetic number, because the mean of its divisors is an integer number (172464411).

Almost surely, 2^673432421 is an apocalyptic number.

It is an amenable number.

673432421 is a deficient number, since it is larger than the sum of its proper divisors (16425223).

673432421 is a wasteful number, since it uses less digits than its factorization.

673432421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16425222.

The product of its digits is 24192, while the sum is 32.

The square root of 673432421 is about 25950.5765061202. The cubic root of 673432421 is about 876.5257389995.

Adding to 673432421 its reverse (124234376), we get a palindrome (797666797).

The spelling of 673432421 in words is "six hundred seventy-three million, four hundred thirty-two thousand, four hundred twenty-one".