6691097840 has 80 divisors (see below), whose sum is σ = 17888521728. Its totient is φ = 2279985408.

The previous prime is 6691097821. The next prime is 6691097843. The reversal of 6691097840 is 487901966.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6691097843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54629 + ... + 127931.

Almost surely, 2^6691097840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6691097840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8944260864).

6691097840 is an abundant number, since it is smaller than the sum of its proper divisors (11197423888).

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

6691097840 is a wasteful number, since it uses less digits than its factorization.

6691097840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73486 (or 73480 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 50.

The square root of 6691097840 is about 81799.1310467293. The cubic root of 6691097840 is about 1884.3683164609.

The spelling of 6691097840 in words is "six billion, six hundred ninety-one million, ninety-seven thousand, eight hundred forty".