66550257 has 36 divisors (see below), whose sum is σ = 105287364. Its totient is φ = 40343040.

The previous prime is 66550243. The next prime is 66550303. The reversal of 66550257 is 75205566.

It can be written as a sum of positive squares in 2 ways, for example, as 24443136 + 42107121 = 4944^2 + 6489^2 .

It is not a de Polignac number, because 66550257 - 2⁴ = 66550241 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66550657) 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 in 35 ways as a sum of consecutive naturals, for example, 646068 + ... + 646170.

It is an arithmetic number, because the mean of its divisors is an integer number (2924649).

Almost surely, 2^66550257 is an apocalyptic number.

It is an amenable number.

66550257 is a deficient number, since it is larger than the sum of its proper divisors (38737107).

66550257 is a wasteful number, since it uses less digits than its factorization.

66550257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270 (or 164 counting only the distinct ones).

The product of its (nonzero) digits is 63000, while the sum is 36.

The square root of 66550257 is about 8157.8340875504. The cubic root of 66550257 is about 405.2439865005.

The spelling of 66550257 in words is "sixty-six million, five hundred fifty thousand, two hundred fifty-seven".