66640163 has 8 divisors (see below), whose sum is σ = 70461120. Its totient is φ = 62850600.

The previous prime is 66640159. The next prime is 66640199. The reversal of 66640163 is 36104666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66640163 - 2² = 66640159 is a prime.

It is a super-2 number, since 2×66640163² = 8881822649333138, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66640363) 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, 3413 + ... + 12038.

It is an arithmetic number, because the mean of its divisors is an integer number (8807640).

Almost surely, 2^66640163 is an apocalyptic number.

66640163 is a deficient number, since it is larger than the sum of its proper divisors (3820957).

66640163 is a wasteful number, since it uses less digits than its factorization.

66640163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15697.

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 66640163 is about 8163.3426364450. The cubic root of 66640163 is about 405.4263923645.

The spelling of 66640163 in words is "sixty-six million, six hundred forty thousand, one hundred sixty-three".