66633857 has 2 divisors, whose sum is σ = 66633858. Its totient is φ = 66633856.

The previous prime is 66633739. The next prime is 66633869. The reversal of 66633857 is 75833666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49336576 + 17297281 = 7024^2 + 4159^2 .

It is a cyclic number.

It is not a de Polignac number, because 66633857 - 2¹⁶ = 66568321 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66633877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33316928 + 33316929.

It is an arithmetic number, because the mean of its divisors is an integer number (33316929).

Almost surely, 2^66633857 is an apocalyptic number.

It is an amenable number.

66633857 is a deficient number, since it is larger than the sum of its proper divisors (1).

66633857 is an equidigital number, since it uses as much as digits as its factorization.

66633857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 544320, while the sum is 44.

The square root of 66633857 is about 8162.9563884661. The cubic root of 66633857 is about 405.4136037830.

The spelling of 66633857 in words is "sixty-six million, six hundred thirty-three thousand, eight hundred fifty-seven".