1688988465 has 12 divisors (see below), whose sum is σ = 2927580084. Its totient is φ = 900793824.

The previous prime is 1688988439. The next prime is 1688988487. The reversal of 1688988465 is 5648898861.

1688988465 is a `hidden beast` number, since 1 + 6 + 88 + 98 + 8 + 465 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 687645729 + 1001342736 = 26223^2 + 31644^2 .

It is not a de Polignac number, because 1688988465 - 2¹¹ = 1688986417 is a prime.

It is a super-3 number, since 3×1688988465³ (a number of 29 digits) contains 333 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18766494 + ... + 18766583.

It is an arithmetic number, because the mean of its divisors is an integer number (243965007).

Almost surely, 2^1688988465 is an apocalyptic number.

1688988465 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1688988465 is a deficient number, since it is larger than the sum of its proper divisors (1238591619).

1688988465 is a wasteful number, since it uses less digits than its factorization.

1688988465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37533088 (or 37533085 counting only the distinct ones).

The product of its digits is 26542080, while the sum is 63.

The square root of 1688988465 is about 41097.3048386387. The cubic root of 1688988465 is about 1190.9007292050.

The spelling of 1688988465 in words is "one billion, six hundred eighty-eight million, nine hundred eighty-eight thousand, four hundred sixty-five".