66720007 has 12 divisors (see below), whose sum is σ = 68901840. Its totient is φ = 64596576.

The previous prime is 66719971. The next prime is 66720011. The reversal of 66720007 is 70002766.

66720007 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66720007 - 2¹⁵ = 66687239 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 (66720037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 399438 + ... + 399604.

It is an arithmetic number, because the mean of its divisors is an integer number (5741820).

Almost surely, 2^66720007 is an apocalyptic number.

66720007 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

66720007 is a deficient number, since it is larger than the sum of its proper divisors (2181833).

66720007 is an equidigital number, since it uses as much as digits as its factorization.

66720007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 66720007 is about 8168.2315711542. The cubic root of 66720007 is about 405.5882464366.

The spelling of 66720007 in words is "sixty-six million, seven hundred twenty thousand, seven".