66556560 has 160 divisors (see below), whose sum is σ = 238199040. Its totient is φ = 15058944.

The previous prime is 66556531. The next prime is 66556573. The reversal of 66556560 is 6565566.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 290526 + ... + 290754.

It is an arithmetic number, because the mean of its divisors is an integer number (1488744).

Almost surely, 2^66556560 is an apocalyptic number.

66556560 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 66556560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119099520).

66556560 is an abundant number, since it is smaller than the sum of its proper divisors (171642480).

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

66556560 is a wasteful number, since it uses less digits than its factorization.

66556560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 419 counting only the distinct ones).

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

The square root of 66556560 is about 8158.2203941791. The cubic root of 66556560 is about 405.2567797004.

The spelling of 66556560 in words is "sixty-six million, five hundred fifty-six thousand, five hundred sixty".