6909686889840 has 720 divisors, whose sum is σ = 27776717703072. Its totient is φ = 1533703901184.

The previous prime is 6909686889839. The next prime is 6909686889857. The reversal of 6909686889840 is 489886869096.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (720).

It is a self number, because there is not a number n which added to its sum of digits gives 6909686889840.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 714027082 + ... + 714036758.

Almost surely, 2^{6909686889840} is an apocalyptic number.

6909686889840 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 6909686889840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13888358851536).

6909686889840 is an abundant number, since it is smaller than the sum of its proper divisors (20867030813232).

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

6909686889840 is a wasteful number, since it uses less digits than its factorization.

6909686889840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10294 (or 10278 counting only the distinct ones).

The product of its (nonzero) digits is 2579890176, while the sum is 81.

The spelling of 6909686889840 in words is "six trillion, nine hundred nine billion, six hundred eighty-six million, eight hundred eighty-nine thousand, eight hundred forty".