681291869 has 2 divisors, whose sum is σ = 681291870. Its totient is φ = 681291868.

The previous prime is 681291857. The next prime is 681291889. The reversal of 681291869 is 968192186.

It is a happy number.

681291869 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 573027844 + 108264025 = 23938^2 + 10405^2 .

It is a cyclic number.

It is not a de Polignac number, because 681291869 - 2¹² = 681287773 is a prime.

It is a super-2 number, since 2×681291869² = 928317221531026322, which contains 22 as substring.

It is a congruent number.

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, 340645934 + 340645935.

It is an arithmetic number, because the mean of its divisors is an integer number (340645935).

Almost surely, 2^681291869 is an apocalyptic number.

It is an amenable number.

681291869 is a deficient number, since it is larger than the sum of its proper divisors (1).

681291869 is an equidigital number, since it uses as much as digits as its factorization.

681291869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 50.

The square root of 681291869 is about 26101.5683245279. The cubic root of 681291869 is about 879.9224574408.

The spelling of 681291869 in words is "six hundred eighty-one million, two hundred ninety-one thousand, eight hundred sixty-nine".