66664751 has 2 divisors, whose sum is σ = 66664752. Its totient is φ = 66664750.

The previous prime is 66664733. The next prime is 66664757. The reversal of 66664751 is 15746666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66664751 - 2¹⁴ = 66648367 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66664699 and 66664708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66664757) 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, 33332375 + 33332376.

It is an arithmetic number, because the mean of its divisors is an integer number (33332376).

Almost surely, 2^66664751 is an apocalyptic number.

66664751 is a deficient number, since it is larger than the sum of its proper divisors (1).

66664751 is an equidigital number, since it uses as much as digits as its factorization.

66664751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 41.

The square root of 66664751 is about 8164.8484982883. The cubic root of 66664751 is about 405.4762491772.

The spelling of 66664751 in words is "sixty-six million, six hundred sixty-four thousand, seven hundred fifty-one".