66555851 has 2 divisors, whose sum is σ = 66555852. Its totient is φ = 66555850.

The previous prime is 66555847. The next prime is 66555887. The reversal of 66555851 is 15855566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66555851 - 2² = 66555847 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66555799 and 66555808.

It is not a weakly prime, because it can be changed into another prime (60555851) 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, 33277925 + 33277926.

It is an arithmetic number, because the mean of its divisors is an integer number (33277926).

Almost surely, 2^66555851 is an apocalyptic number.

66555851 is a deficient number, since it is larger than the sum of its proper divisors (1).

66555851 is an equidigital number, since it uses as much as digits as its factorization.

66555851 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180000, while the sum is 41.

The square root of 66555851 is about 8158.1769409593. The cubic root of 66555851 is about 405.2553406833.

The spelling of 66555851 in words is "sixty-six million, five hundred fifty-five thousand, eight hundred fifty-one".