681043873 has 2 divisors, whose sum is σ = 681043874. Its totient is φ = 681043872.

The previous prime is 681043871. The next prime is 681043877. The reversal of 681043873 is 378340186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 491375889 + 189667984 = 22167^2 + 13772^2 .

It is a cyclic number.

It is not a de Polignac number, because 681043873 - 2¹ = 681043871 is a prime.

Together with 681043871, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (681043871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340521936 + 340521937.

It is an arithmetic number, because the mean of its divisors is an integer number (340521937).

Almost surely, 2^681043873 is an apocalyptic number.

It is an amenable number.

681043873 is a deficient number, since it is larger than the sum of its proper divisors (1).

681043873 is an equidigital number, since it uses as much as digits as its factorization.

681043873 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 681043873 is about 26096.8172963678. The cubic root of 681043873 is about 879.8156780791.

The spelling of 681043873 in words is "six hundred eighty-one million, forty-three thousand, eight hundred seventy-three".