66680655 has 16 divisors (see below), whose sum is σ = 107727360. Its totient is φ = 35216928.

The previous prime is 66680591. The next prime is 66680687. The reversal of 66680655 is 55608666.

It is not a de Polignac number, because 66680655 - 2⁶ = 66680591 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20035 + ... + 23124.

It is an arithmetic number, because the mean of its divisors is an integer number (6732960).

Almost surely, 2^66680655 is an apocalyptic number.

66680655 is a deficient number, since it is larger than the sum of its proper divisors (41046705).

66680655 is a wasteful number, since it uses less digits than its factorization.

66680655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43270.

The product of its (nonzero) digits is 259200, while the sum is 42.

The square root of 66680655 is about 8165.8223713231. The cubic root of 66680655 is about 405.5084910112.

The spelling of 66680655 in words is "sixty-six million, six hundred eighty thousand, six hundred fifty-five".