673161921 has 10 divisors (see below), whose sum is σ = 1005587682. Its totient is φ = 448774560.

The previous prime is 673161919. The next prime is 673161943. The reversal of 673161921 is 129161376.

673161921 is a `hidden beast` number, since 6 + 7 + 31 + 619 + 2 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 411887025 + 261274896 = 20295^2 + 16164^2 .

It is not a de Polignac number, because 673161921 - 2¹ = 673161919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (673161911) 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, 4155240 + ... + 4155401.

Almost surely, 2^673161921 is an apocalyptic number.

It is an amenable number.

673161921 is a deficient number, since it is larger than the sum of its proper divisors (332425761).

673161921 is an equidigital number, since it uses as much as digits as its factorization.

673161921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8310653 (or 8310644 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 673161921 is about 25945.3641523876. The cubic root of 673161921 is about 876.4083642105.

The spelling of 673161921 in words is "six hundred seventy-three million, one hundred sixty-one thousand, nine hundred twenty-one".