686109026 has 4 divisors (see below), whose sum is σ = 1029163542. Its totient is φ = 343054512.

The previous prime is 686109023. The next prime is 686109037. The reversal of 686109026 is 620901686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 620901686 = 2 ⋅310450843.

It can be written as a sum of positive squares in only one way, i.e., 653058025 + 33051001 = 25555^2 + 5749^2 .

It is not an unprimeable number, because it can be changed into a prime (686109023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171527255 + ... + 171527258.

Almost surely, 2^686109026 is an apocalyptic number.

686109026 is a deficient number, since it is larger than the sum of its proper divisors (343054516).

686109026 is a wasteful number, since it uses less digits than its factorization.

686109026 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343054515.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 686109026 is about 26193.6829407397. The cubic root of 686109026 is about 881.9914549522.

The spelling of 686109026 in words is "six hundred eighty-six million, one hundred nine thousand, twenty-six".