1688652557 has 4 divisors (see below), whose sum is σ = 1720513980. Its totient is φ = 1656791136.

The previous prime is 1688652503. The next prime is 1688652599. The reversal of 1688652557 is 7552568861.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 723556201 + 965096356 = 26899^2 + 31066^2 .

It is a cyclic number.

It is not a de Polignac number, because 1688652557 - 2¹⁸ = 1688390413 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (53), and also a Moran number because the ratio is a prime number: 31861369 = 1688652557 / (1 + 6 + 8 + 8 + 6 + 5 + 2 + 5 + 5 + 7).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1688652499 and 1688652508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688652257) 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, 15930632 + ... + 15930737.

It is an arithmetic number, because the mean of its divisors is an integer number (430128495).

Almost surely, 2^1688652557 is an apocalyptic number.

It is an amenable number.

1688652557 is a deficient number, since it is larger than the sum of its proper divisors (31861423).

1688652557 is an equidigital number, since it uses as much as digits as its factorization.

1688652557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31861422.

The product of its digits is 4032000, while the sum is 53.

The square root of 1688652557 is about 41093.2178954143. The cubic root of 1688652557 is about 1190.8217747276.

The spelling of 1688652557 in words is "one billion, six hundred eighty-eight million, six hundred fifty-two thousand, five hundred fifty-seven".