1686720055 has 4 divisors (see below), whose sum is σ = 2024064072. Its totient is φ = 1349376040.

The previous prime is 1686720047. The next prime is 1686720097. The reversal of 1686720055 is 5500276861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5500276861 = 487 ⋅11294203.

It is not a de Polignac number, because 1686720055 - 2³ = 1686720047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168672001 + ... + 168672010.

It is an arithmetic number, because the mean of its divisors is an integer number (506016018).

Almost surely, 2^1686720055 is an apocalyptic number.

1686720055 is a deficient number, since it is larger than the sum of its proper divisors (337344017).

1686720055 is an equidigital number, since it uses as much as digits as its factorization.

1686720055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337344016.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 1686720055 is about 41069.6975274959. The cubic root of 1686720055 is about 1190.3673406345.

The spelling of 1686720055 in words is "one billion, six hundred eighty-six million, seven hundred twenty thousand, fifty-five".