66381055 has 16 divisors (see below), whose sum is σ = 86163840. Its totient is φ = 48803328.

The previous prime is 66381047. The next prime is 66381113. The reversal of 66381055 is 55018366.

It is a cyclic number.

It is not a de Polignac number, because 66381055 - 2³ = 66381047 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66381055.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 13399 + ... + 17671.

It is an arithmetic number, because the mean of its divisors is an integer number (5385240).

Almost surely, 2^66381055 is an apocalyptic number.

66381055 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66381055 is a deficient number, since it is larger than the sum of its proper divisors (19782785).

66381055 is a wasteful number, since it uses less digits than its factorization.

66381055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4530.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 66381055 is about 8147.4569652131. The cubic root of 66381055 is about 404.9002548653.

It can be divided in two parts, 663 and 81055, that added together give a palindrome (81718).

The spelling of 66381055 in words is "sixty-six million, three hundred eighty-one thousand, fifty-five".