66565560 has 64 divisors (see below), whose sum is σ = 201204000. Its totient is φ = 17616896.

The previous prime is 66565549. The next prime is 66565567. The reversal of 66565560 is 6556566.

It is a happy number.

It is a super-2 number, since 2×66565560² = 8861947556227200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66565567) 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, 14416 + ... + 18464.

Almost surely, 2^66565560 is an apocalyptic number.

66565560 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 66565560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100602000).

66565560 is an abundant number, since it is smaller than the sum of its proper divisors (134638440).

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

66565560 is a wasteful number, since it uses less digits than its factorization.

66565560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4200 (or 4196 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 39.

The square root of 66565560 is about 8158.7719664175. The cubic root of 66565560 is about 405.2750456015.

The spelling of 66565560 in words is "sixty-six million, five hundred sixty-five thousand, five hundred sixty".