1688666555 has 8 divisors (see below), whose sum is σ = 2114504352. Its totient is φ = 1292196928.

The previous prime is 1688666543. The next prime is 1688666557. The reversal of 1688666555 is 5556668861.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1688666555 - 2⁸ = 1688666299 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1688666555.

It is not an unprimeable number, because it can be changed into a prime (1688666557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7341914 + ... + 7342143.

It is an arithmetic number, because the mean of its divisors is an integer number (264313044).

Almost surely, 2^1688666555 is an apocalyptic number.

1688666555 is a deficient number, since it is larger than the sum of its proper divisors (425837797).

1688666555 is a wasteful number, since it uses less digits than its factorization.

1688666555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14684085.

The product of its digits is 10368000, while the sum is 56.

The square root of 1688666555 is about 41093.3882151375. The cubic root of 1688666555 is about 1190.8250651374.

The spelling of 1688666555 in words is "one billion, six hundred eighty-eight million, six hundred sixty-six thousand, five hundred fifty-five".