6661115929920 has 224 divisors, whose sum is σ = 21705389607168. Its totient is φ = 1730059681792.

The previous prime is 6661115929907. The next prime is 6661115929933. The reversal of 6661115929920 is 299295111666.

It is an interprime number because it is at equal distance from previous prime (6661115929907) and next prime (6661115929933).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6492757 + ... + 7448363.

Almost surely, 2^{6661115929920} is an apocalyptic number.

6661115929920 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 6661115929920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10852694803584).

6661115929920 is an abundant number, since it is smaller than the sum of its proper divisors (15044273677248).

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

6661115929920 is a wasteful number, since it uses less digits than its factorization.

6661115929920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 955817 (or 955807 counting only the distinct ones).

The product of its (nonzero) digits is 3149280, while the sum is 57.

The spelling of 6661115929920 in words is "six trillion, six hundred sixty-one billion, one hundred fifteen million, nine hundred twenty-nine thousand, nine hundred twenty".