66855293 has 2 divisors, whose sum is σ = 66855294. Its totient is φ = 66855292.

The previous prime is 66855199. The next prime is 66855307. The reversal of 66855293 is 39255866.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64673764 + 2181529 = 8042^2 + 1477^2 .

It is a cyclic number.

It is not a de Polignac number, because 66855293 - 2⁸ = 66855037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66855193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33427646 + 33427647.

It is an arithmetic number, because the mean of its divisors is an integer number (33427647).

Almost surely, 2^66855293 is an apocalyptic number.

It is an amenable number.

66855293 is a deficient number, since it is larger than the sum of its proper divisors (1).

66855293 is an equidigital number, since it uses as much as digits as its factorization.

66855293 is an evil number, because the sum of its binary digits is even.

The product of its digits is 388800, while the sum is 44.

The square root of 66855293 is about 8176.5086069789. The cubic root of 66855293 is about 405.8621940843.

The spelling of 66855293 in words is "sixty-six million, eight hundred fifty-five thousand, two hundred ninety-three".