686388082 has 4 divisors (see below), whose sum is σ = 1029582126. Its totient is φ = 343194040.

The previous prime is 686388067. The next prime is 686388083. The reversal of 686388082 is 280883686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 280883686 = 2 ⋅140441843.

It can be written as a sum of positive squares in only one way, i.e., 381850681 + 304537401 = 19541^2 + 17451^2 .

It is a super-2 number, since 2×686388082² = 942257198223277448, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (686388083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171597019 + ... + 171597022.

Almost surely, 2^686388082 is an apocalyptic number.

686388082 is a deficient number, since it is larger than the sum of its proper divisors (343194044).

686388082 is a wasteful number, since it uses less digits than its factorization.

686388082 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343194043.

The product of its (nonzero) digits is 884736, while the sum is 49.

The square root of 686388082 is about 26199.0091797381. The cubic root of 686388082 is about 882.1110140104. Note that the first 3 decimals are identical.

The spelling of 686388082 in words is "six hundred eighty-six million, three hundred eighty-eight thousand, eighty-two".