66505560 has 64 divisors (see below), whose sum is σ = 217658880. Its totient is φ = 16122240.

The previous prime is 66505559. The next prime is 66505561. The reversal of 66505560 is 6550566.

It is an interprime number because it is at equal distance from previous prime (66505559) and next prime (66505561).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66505561) 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, 23872 + ... + 26511.

It is an arithmetic number, because the mean of its divisors is an integer number (3400920).

Almost surely, 2^66505560 is an apocalyptic number.

66505560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66505560 is an abundant number, since it is smaller than the sum of its proper divisors (151153320).

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

66505560 is a wasteful number, since it uses less digits than its factorization.

66505560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50408 (or 50404 counting only the distinct ones).

The product of its (nonzero) digits is 27000, while the sum is 33.

The square root of 66505560 is about 8155.0941134974. The cubic root of 66505560 is about 405.1532418117.

The spelling of 66505560 in words is "sixty-six million, five hundred five thousand, five hundred sixty".