686659387 has 2 divisors, whose sum is σ = 686659388. Its totient is φ = 686659386.

The previous prime is 686659367. The next prime is 686659397. The reversal of 686659387 is 783956686.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686659387 is a prime.

It is a super-2 number, since 2×686659387² = 943002227510431538, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (686659367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343329693 + 343329694.

It is an arithmetic number, because the mean of its divisors is an integer number (343329694).

Almost surely, 2^686659387 is an apocalyptic number.

686659387 is a deficient number, since it is larger than the sum of its proper divisors (1).

686659387 is an equidigital number, since it uses as much as digits as its factorization.

686659387 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13063680, while the sum is 58.

The square root of 686659387 is about 26204.1864403381. The cubic root of 686659387 is about 882.2272211582.

The spelling of 686659387 in words is "six hundred eighty-six million, six hundred fifty-nine thousand, three hundred eighty-seven".