665528555520 has 576 divisors, whose sum is σ = 2532900857760. Its totient is φ = 167024001024.

The previous prime is 665528555479. The next prime is 665528555533. The reversal of 665528555520 is 25555825566.

665528555520 is a `hidden beast` number, since 6 + 6 + 5 + 5 + 2 + 85 + 5 + 552 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42293574 + ... + 42309306.

Almost surely, 2^665528555520 is an apocalyptic number.

665528555520 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 665528555520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1266450428880).

665528555520 is an abundant number, since it is smaller than the sum of its proper divisors (1867372302240).

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

665528555520 is a wasteful number, since it uses less digits than its factorization.

665528555520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15792 (or 15760 counting only the distinct ones).

The product of its (nonzero) digits is 18000000, while the sum is 54.

The spelling of 665528555520 in words is "six hundred sixty-five billion, five hundred twenty-eight million, five hundred fifty-five thousand, five hundred twenty".