673861681 has 2 divisors, whose sum is σ = 673861682. Its totient is φ = 673861680.

The previous prime is 673861673. The next prime is 673861709. The reversal of 673861681 is 186168376.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 664350625 + 9511056 = 25775^2 + 3084^2 .

It is a cyclic number.

It is not a de Polignac number, because 673861681 - 2³ = 673861673 is a prime.

It is a super-2 number, since 2×673861681² = 908179130240291522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (673861651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 336930840 + 336930841.

It is an arithmetic number, because the mean of its divisors is an integer number (336930841).

Almost surely, 2^673861681 is an apocalyptic number.

It is an amenable number.

673861681 is a deficient number, since it is larger than the sum of its proper divisors (1).

673861681 is an equidigital number, since it uses as much as digits as its factorization.

673861681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 46.

The square root of 673861681 is about 25958.8459104021. The cubic root of 673861681 is about 876.7119380947.

The spelling of 673861681 in words is "six hundred seventy-three million, eight hundred sixty-one thousand, six hundred eighty-one".