66906647 has 2 divisors, whose sum is σ = 66906648. Its totient is φ = 66906646.

The previous prime is 66906643. The next prime is 66906703. The reversal of 66906647 is 74660966.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66906647 - 2² = 66906643 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66906598 and 66906607.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66906641) 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 as a sum of consecutive naturals, namely, 33453323 + 33453324.

It is an arithmetic number, because the mean of its divisors is an integer number (33453324).

Almost surely, 2^66906647 is an apocalyptic number.

66906647 is a deficient number, since it is larger than the sum of its proper divisors (1).

66906647 is an equidigital number, since it uses as much as digits as its factorization.

66906647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 44.

The square root of 66906647 is about 8179.6483420744. The cubic root of 66906647 is about 405.9660866947.

The spelling of 66906647 in words is "sixty-six million, nine hundred six thousand, six hundred forty-seven".