686128099 has 2 divisors, whose sum is σ = 686128100. Its totient is φ = 686128098.

The previous prime is 686128087. The next prime is 686128127. The reversal of 686128099 is 990821686.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 686128099 - 2⁷ = 686127971 is a prime.

It is not a weakly prime, because it can be changed into another prime (686128699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343064049 + 343064050.

It is an arithmetic number, because the mean of its divisors is an integer number (343064050).

Almost surely, 2^686128099 is an apocalyptic number.

686128099 is a deficient number, since it is larger than the sum of its proper divisors (1).

686128099 is an equidigital number, since it uses as much as digits as its factorization.

686128099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 373248, while the sum is 49.

The square root of 686128099 is about 26194.0470145413. The cubic root of 686128099 is about 881.9996276413. Note that the first 3 decimals are identical.

The spelling of 686128099 in words is "six hundred eighty-six million, one hundred twenty-eight thousand, ninety-nine".