681188869 has 2 divisors, whose sum is σ = 681188870. Its totient is φ = 681188868.

The previous prime is 681188867. The next prime is 681188873. The reversal of 681188869 is 968881186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 609447969 + 71740900 = 24687^2 + 8470^2 .

It is a cyclic number.

It is not a de Polignac number, because 681188869 - 2¹ = 681188867 is a prime.

It is a super-2 number, since 2×681188869² = 928036550498998322, which contains 22 as substring.

Together with 681188867, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (681188867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340594434 + 340594435.

It is an arithmetic number, because the mean of its divisors is an integer number (340594435).

Almost surely, 2^681188869 is an apocalyptic number.

It is an amenable number.

681188869 is a deficient number, since it is larger than the sum of its proper divisors (1).

681188869 is an equidigital number, since it uses as much as digits as its factorization.

681188869 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1327104, while the sum is 55.

The square root of 681188869 is about 26099.5951884316. The cubic root of 681188869 is about 879.8781119921.

The spelling of 681188869 in words is "six hundred eighty-one million, one hundred eighty-eight thousand, eight hundred sixty-nine".