6689809440 has 288 divisors, whose sum is σ = 24707120256. Its totient is φ = 1706158080.

The previous prime is 6689809411. The next prime is 6689809447. The reversal of 6689809440 is 449089866.

It is a tau number, because it is divible by the number of its divisors (288).

It is a super-2 number, since 2×6689809440² = 89507100687026227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (6689809447) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 890500 + ... + 897980.

It is an arithmetic number, because the mean of its divisors is an integer number (85788612).

Almost surely, 2^6689809440 is an apocalyptic number.

6689809440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6689809440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12353560128).

6689809440 is an abundant number, since it is smaller than the sum of its proper divisors (18017310816).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6689809440 is a wasteful number, since it uses less digits than its factorization.

6689809440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7534 (or 7514 counting only the distinct ones).

The product of its (nonzero) digits is 2985984, while the sum is 54.

The square root of 6689809440 is about 81791.2552782998. The cubic root of 6689809440 is about 1884.2473609246.

The spelling of 6689809440 in words is "six billion, six hundred eighty-nine million, eight hundred nine thousand, four hundred forty".