66138241 has 8 divisors (see below), whose sum is σ = 73682280. Its totient is φ = 58945152.

The previous prime is 66138239. The next prime is 66138251. The reversal of 66138241 is 14283166.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 57600 + 66080641 = 240^2 + 8129^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66138241 - 2¹ = 66138239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66138251) 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 in 7 ways as a sum of consecutive naturals, for example, 87340 + ... + 88093.

It is an arithmetic number, because the mean of its divisors is an integer number (9210285).

Almost surely, 2^66138241 is an apocalyptic number.

It is an amenable number.

66138241 is a deficient number, since it is larger than the sum of its proper divisors (7544039).

66138241 is a wasteful number, since it uses less digits than its factorization.

66138241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175475.

The product of its digits is 6912, while the sum is 31.

The square root of 66138241 is about 8132.5420994914. The cubic root of 66138241 is about 404.4059593664.

The spelling of 66138241 in words is "sixty-six million, one hundred thirty-eight thousand, two hundred forty-one".