66651207061655 has 8 divisors (see below), whose sum is σ = 80019882627984. Its totient is φ = 53295342880000.

The previous prime is 66651207061603. The next prime is 66651207061667. The reversal of 66651207061655 is 55616070215666.

It is a happy number.

66651207061655 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 66651207061655 - 2⁶ = 66651207061591 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66651207061655.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3202834721 + ... + 3202855530.

It is an arithmetic number, because the mean of its divisors is an integer number (10002485328498).

Almost surely, 2^{66651207061655} is an apocalyptic number.

66651207061655 is a deficient number, since it is larger than the sum of its proper divisors (13368675566329).

66651207061655 is a wasteful number, since it uses less digits than its factorization.

66651207061655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6405692337.

The product of its (nonzero) digits is 13608000, while the sum is 56.

The spelling of 66651207061655 in words is "sixty-six trillion, six hundred fifty-one billion, two hundred seven million, sixty-one thousand, six hundred fifty-five".