1686866858 has 4 divisors (see below), whose sum is σ = 2530300290. Its totient is φ = 843433428.

The previous prime is 1686866849. The next prime is 1686866869. The reversal of 1686866858 is 8586686861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1679934169 + 6932689 = 40987^2 + 2633^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1686866858.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421716713 + ... + 421716716.

Almost surely, 2^1686866858 is an apocalyptic number.

1686866858 is a deficient number, since it is larger than the sum of its proper divisors (843433432).

1686866858 is an equidigital number, since it uses as much as digits as its factorization.

1686866858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843433431.

The product of its digits is 26542080, while the sum is 62.

The square root of 1686866858 is about 41071.4847308933. The cubic root of 1686866858 is about 1190.4018740132.

The spelling of 1686866858 in words is "one billion, six hundred eighty-six million, eight hundred sixty-six thousand, eight hundred fifty-eight".