66640849 has 8 divisors (see below), whose sum is σ = 73136448. Its totient is φ = 60218160.

The previous prime is 66640831. The next prime is 66640859. The reversal of 66640849 is 94804666.

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 66640849 - 2⁹ = 66640337 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66640829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16302 + ... + 19975.

It is an arithmetic number, because the mean of its divisors is an integer number (9142056).

Almost surely, 2^66640849 is an apocalyptic number.

It is an amenable number.

66640849 is a deficient number, since it is larger than the sum of its proper divisors (6495599).

66640849 is a wasteful number, since it uses less digits than its factorization.

66640849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36455.

The product of its (nonzero) digits is 248832, while the sum is 43.

The square root of 66640849 is about 8163.3846534388. The cubic root of 66640849 is about 405.4277835254.

The spelling of 66640849 in words is "sixty-six million, six hundred forty thousand, eight hundred forty-nine".