1688538517 has 4 divisors (see below), whose sum is σ = 1701428256. Its totient is φ = 1675648780.

The previous prime is 1688538479. The next prime is 1688538529. The reversal of 1688538517 is 7158358861.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1688538517 - 2⁷ = 1688538389 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 (1688535517) 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, 6444673 + ... + 6444934.

It is an arithmetic number, because the mean of its divisors is an integer number (425357064).

Almost surely, 2^1688538517 is an apocalyptic number.

It is an amenable number.

1688538517 is a deficient number, since it is larger than the sum of its proper divisors (12889739).

1688538517 is a wasteful number, since it uses less digits than its factorization.

1688538517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12889738.

The product of its digits is 1612800, while the sum is 52.

The square root of 1688538517 is about 41091.8302950842. The cubic root of 1688538517 is about 1190.7949674818.

The spelling of 1688538517 in words is "one billion, six hundred eighty-eight million, five hundred thirty-eight thousand, five hundred seventeen".