66805451 has 2 divisors, whose sum is σ = 66805452. Its totient is φ = 66805450.

The previous prime is 66805433. The next prime is 66805457. The reversal of 66805451 is 15450866.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66805451 - 2¹⁴ = 66789067 is a prime.

It is not a weakly prime, because it can be changed into another prime (66805457) 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, 33402725 + 33402726.

It is an arithmetic number, because the mean of its divisors is an integer number (33402726).

Almost surely, 2^66805451 is an apocalyptic number.

66805451 is a deficient number, since it is larger than the sum of its proper divisors (1).

66805451 is an equidigital number, since it uses as much as digits as its factorization.

66805451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28800, while the sum is 35.

The square root of 66805451 is about 8173.4601607887. The cubic root of 66805451 is about 405.7613094637.

The spelling of 66805451 in words is "sixty-six million, eight hundred five thousand, four hundred fifty-one".