66656005 has 8 divisors (see below), whose sum is σ = 86140152. Its totient is φ = 49222848.

The previous prime is 66655999. The next prime is 66656027. The reversal of 66656005 is 50065666.

It can be written as a sum of positive squares in 4 ways, for example, as 11792356 + 54863649 = 3434^2 + 7407^2 .

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 66656005 - 2⁷ = 66655877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 512674 + ... + 512803.

It is an arithmetic number, because the mean of its divisors is an integer number (10767519).

Almost surely, 2^66656005 is an apocalyptic number.

66656005 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66656005 is a deficient number, since it is larger than the sum of its proper divisors (19484147).

66656005 is a wasteful number, since it uses less digits than its factorization.

66656005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1025495.

The product of its (nonzero) digits is 32400, while the sum is 34.

The square root of 66656005 is about 8164.3128920932. The cubic root of 66656005 is about 405.4585164157.

The spelling of 66656005 in words is "sixty-six million, six hundred fifty-six thousand, five".