66711770 has 16 divisors (see below), whose sum is σ = 120889800. Its totient is φ = 26505024.

The previous prime is 66711769. The next prime is 66711773. The reversal of 66711770 is 7711766.

It can be written as a sum of positive squares in 4 ways, for example, as 45981961 + 20729809 = 6781^2 + 4553^2 .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66711770.

It is not an unprimeable number, because it can be changed into a prime (66711773) 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, 20897 + ... + 23876.

Almost surely, 2^66711770 is an apocalyptic number.

66711770 is a deficient number, since it is larger than the sum of its proper divisors (54178030).

66711770 is a wasteful number, since it uses less digits than its factorization.

66711770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44929.

The product of its (nonzero) digits is 12348, while the sum is 35.

The square root of 66711770 is about 8167.7273460859. The cubic root of 66711770 is about 405.5715549522.

The spelling of 66711770 in words is "sixty-six million, seven hundred eleven thousand, seven hundred seventy".