1688551855 has 4 divisors (see below), whose sum is σ = 2026262232. Its totient is φ = 1350841480.

The previous prime is 1688551853. The next prime is 1688551859. The reversal of 1688551855 is 5581558861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5581558861 = 34211 ⋅163151.

It is not a de Polignac number, because 1688551855 - 2¹ = 1688551853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688551853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168855181 + ... + 168855190.

It is an arithmetic number, because the mean of its divisors is an integer number (506565558).

Almost surely, 2^1688551855 is an apocalyptic number.

1688551855 is a deficient number, since it is larger than the sum of its proper divisors (337710377).

1688551855 is an equidigital number, since it uses as much as digits as its factorization.

1688551855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337710376.

The product of its digits is 1920000, while the sum is 52.

The square root of 1688551855 is about 41091.9925897978. The cubic root of 1688551855 is about 1190.7981028918.

The spelling of 1688551855 in words is "one billion, six hundred eighty-eight million, five hundred fifty-one thousand, eight hundred fifty-five".