66005643 has 16 divisors (see below), whose sum is σ = 96256512. Its totient is φ = 39900000.

The previous prime is 66005633. The next prime is 66005657. The reversal of 66005643 is 34650066.

It is not a de Polignac number, because 66005643 - 2⁶ = 66005579 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66005643.

It is not an unprimeable number, because it can be changed into a prime (66005623) 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, 11518 + ... + 16268.

It is an arithmetic number, because the mean of its divisors is an integer number (6016032).

Almost surely, 2^66005643 is an apocalyptic number.

66005643 is a deficient number, since it is larger than the sum of its proper divisors (30250869).

66005643 is a wasteful number, since it uses less digits than its factorization.

66005643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5186.

The product of its (nonzero) digits is 12960, while the sum is 30.

The square root of 66005643 is about 8124.3856998545. The cubic root of 66005643 is about 404.1355192680.

The spelling of 66005643 in words is "sixty-six million, five thousand, six hundred forty-three".