6690665520 has 960 divisors, whose sum is σ = 30752317440. Its totient is φ = 1260748800.

The previous prime is 6690665507. The next prime is 6690665557. The reversal of 6690665520 is 255660966.

6690665520 is a `hidden beast` number, since 6 + 6 + 90 + 6 + 6 + 552 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 29216766 + ... + 29216994.

It is an arithmetic number, because the mean of its divisors is an integer number (32033664).

Almost surely, 2^6690665520 is an apocalyptic number.

6690665520 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 6690665520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15376158720).

6690665520 is an abundant number, since it is smaller than the sum of its proper divisors (24061651920).

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

6690665520 is a wasteful number, since it uses less digits than its factorization.

6690665520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314 (or 305 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 45.

The square root of 6690665520 is about 81796.4884331840. The cubic root of 6690665520 is about 1884.3277318077.

The spelling of 6690665520 in words is "six billion, six hundred ninety million, six hundred sixty-five thousand, five hundred twenty".