66645580 has 12 divisors (see below), whose sum is σ = 139955760. Its totient is φ = 26658224.

The previous prime is 66645517. The next prime is 66645583. The reversal of 66645580 is 8554666.

It is not an unprimeable number, because it can be changed into a prime (66645583) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666120 + ... + 1666159.

It is an arithmetic number, because the mean of its divisors is an integer number (11662980).

Almost surely, 2^66645580 is an apocalyptic number.

It is an amenable number.

66645580 is an abundant number, since it is smaller than the sum of its proper divisors (73310180).

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

66645580 is a wasteful number, since it uses less digits than its factorization.

66645580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3332288 (or 3332286 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 40.

The square root of 66645580 is about 8163.6744178097. The cubic root of 66645580 is about 405.4373774080.

The spelling of 66645580 in words is "sixty-six million, six hundred forty-five thousand, five hundred eighty".