66156655 has 4 divisors (see below), whose sum is σ = 79387992. Its totient is φ = 52925320.

The previous prime is 66156617. The next prime is 66156659. The reversal of 66156655 is 55665166.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66156655 - 2⁹ = 66156143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66156659) 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 3 ways as a sum of consecutive naturals, for example, 6615661 + ... + 6615670.

It is an arithmetic number, because the mean of its divisors is an integer number (19846998).

Almost surely, 2^66156655 is an apocalyptic number.

66156655 is a deficient number, since it is larger than the sum of its proper divisors (13231337).

66156655 is a wasteful number, since it uses less digits than its factorization.

66156655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13231336.

The product of its digits is 162000, while the sum is 40.

The square root of 66156655 is about 8133.6741390346. The cubic root of 66156655 is about 404.4434870268.

The spelling of 66156655 in words is "sixty-six million, one hundred fifty-six thousand, six hundred fifty-five".