66560644 has 24 divisors (see below), whose sum is σ = 123891768. Its totient is φ = 31180800.

The previous prime is 66560639. The next prime is 66560647. The reversal of 66560644 is 44606566.

It can be written as a sum of positive squares in 4 ways, for example, as 788544 + 65772100 = 888^2 + 8110^2 .

It is not an unprimeable number, because it can be changed into a prime (66560647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13744 + ... + 17944.

It is an arithmetic number, because the mean of its divisors is an integer number (5162157).

Almost surely, 2^66560644 is an apocalyptic number.

It is an amenable number.

66560644 is a deficient number, since it is larger than the sum of its proper divisors (57331124).

66560644 is a wasteful number, since it uses less digits than its factorization.

66560644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4455 (or 4453 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 37.

The square root of 66560644 is about 8158.4706900252. The cubic root of 66560644 is about 405.2650685644.

The spelling of 66560644 in words is "sixty-six million, five hundred sixty thousand, six hundred forty-four".