66840751 has 2 divisors, whose sum is σ = 66840752. Its totient is φ = 66840750.

The previous prime is 66840733. The next prime is 66840757. The reversal of 66840751 is 15704866.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66840751 - 2⁷ = 66840623 is a prime.

It is equal to p_3942919 and since 66840751 and 3942919 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66840751.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66840757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33420375 + 33420376.

It is an arithmetic number, because the mean of its divisors is an integer number (33420376).

Almost surely, 2^66840751 is an apocalyptic number.

66840751 is a deficient number, since it is larger than the sum of its proper divisors (1).

66840751 is an equidigital number, since it uses as much as digits as its factorization.

66840751 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 66840751 is about 8175.6193037592. The cubic root of 66840751 is about 405.8327649708.

The spelling of 66840751 in words is "sixty-six million, eight hundred forty thousand, seven hundred fifty-one".