6661509120 has 416 divisors, whose sum is σ = 27081411840. Its totient is φ = 1521745920.

The previous prime is 6661509091. The next prime is 6661509137. The reversal of 6661509120 is 219051666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 3869860 + ... + 3871580.

Almost surely, 2^6661509120 is an apocalyptic number.

6661509120 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 6661509120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13540705920).

6661509120 is an abundant number, since it is smaller than the sum of its proper divisors (20419902720).

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

6661509120 is a wasteful number, since it uses less digits than its factorization.

6661509120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1766 (or 1738 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 6661509120 is about 81618.0685877827. The cubic root of 6661509120 is about 1881.5865888257.

The spelling of 6661509120 in words is "six billion, six hundred sixty-one million, five hundred nine thousand, one hundred twenty".