1688798513 has 6 divisors (see below), whose sum is σ = 1788319026. Its totient is φ = 1589297952.

The previous prime is 1688798497. The next prime is 1688798521. The reversal of 1688798513 is 3158978861.

It can be written as a sum of positive squares in only one way, i.e., 1589457424 + 99341089 = 39868^2 + 9967^2 .

It is not a de Polignac number, because 1688798513 - 2⁴ = 1688798497 is a prime.

It is a super-2 number, since 2×1688798513² = 5704080835022022338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1688798533) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 164456 + ... + 174422.

It is an arithmetic number, because the mean of its divisors is an integer number (298053171).

Almost surely, 2^1688798513 is an apocalyptic number.

It is an amenable number.

1688798513 is a deficient number, since it is larger than the sum of its proper divisors (99520513).

1688798513 is an frugal number, since it uses more digits than its factorization.

1688798513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19951 (or 9984 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 56.

The square root of 1688798513 is about 41094.9937705312. The cubic root of 1688798513 is about 1190.8560826683.

The spelling of 1688798513 in words is "one billion, six hundred eighty-eight million, seven hundred ninety-eight thousand, five hundred thirteen".