66506560 has 28 divisors (see below), whose sum is σ = 158369508. Its totient is φ = 26602496.

The previous prime is 66506549. The next prime is 66506603. The reversal of 66506560 is 6560566.

It can be written as a sum of positive squares in 2 ways, for example, as 31270464 + 35236096 = 5592^2 + 5936^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 103597 + ... + 104236.

Almost surely, 2^66506560 is an apocalyptic number.

It is an amenable number.

66506560 is an abundant number, since it is smaller than the sum of its proper divisors (91862948).

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

66506560 is a wasteful number, since it uses less digits than its factorization.

66506560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207850 (or 207840 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 66506560 is about 8155.1554246378. The cubic root of 66506560 is about 405.1552724751.

The spelling of 66506560 in words is "sixty-six million, five hundred six thousand, five hundred sixty".