681291889 has 2 divisors, whose sum is σ = 681291890. Its totient is φ = 681291888.

The previous prime is 681291869. The next prime is 681291893. The reversal of 681291889 is 988192186.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 555403489 + 125888400 = 23567^2 + 11220^2 .

It is a cyclic number.

It is not a de Polignac number, because 681291889 - 2⁵ = 681291857 is a prime.

It is not a weakly prime, because it can be changed into another prime (681291829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340645944 + 340645945.

It is an arithmetic number, because the mean of its divisors is an integer number (340645945).

Almost surely, 2^681291889 is an apocalyptic number.

It is an amenable number.

681291889 is a deficient number, since it is larger than the sum of its proper divisors (1).

681291889 is an equidigital number, since it uses as much as digits as its factorization.

681291889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 497664, while the sum is 52.

The square root of 681291889 is about 26101.5687076467. The cubic root of 681291889 is about 879.9224660512.

The spelling of 681291889 in words is "six hundred eighty-one million, two hundred ninety-one thousand, eight hundred eighty-nine".