66515520 has 112 divisors (see below), whose sum is σ = 212872320. Its totient is φ = 17596416.

The previous prime is 66515513. The next prime is 66515521. The reversal of 66515520 is 2551566.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (66515521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 185101 + ... + 185459.

Almost surely, 2^66515520 is an apocalyptic number.

66515520 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 66515520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106436160).

66515520 is an abundant number, since it is smaller than the sum of its proper divisors (146356800).

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

66515520 is a wasteful number, since it uses less digits than its factorization.

66515520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572 (or 562 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 66515520 is about 8155.7047518899. The cubic root of 66515520 is about 405.1734663105.

The spelling of 66515520 in words is "sixty-six million, five hundred fifteen thousand, five hundred twenty".