66831385 has 8 divisors (see below), whose sum is σ = 80385480. Its totient is φ = 53339904.

The previous prime is 66831383. The next prime is 66831389. The reversal of 66831385 is 58313866.

It can be written as a sum of positive squares in 4 ways, for example, as 2238016 + 64593369 = 1496^2 + 8037^2 .

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 66831385 - 2¹ = 66831383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66831383) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13270 + ... + 17599.

It is an arithmetic number, because the mean of its divisors is an integer number (10048185).

Almost surely, 2^66831385 is an apocalyptic number.

It is an amenable number.

66831385 is a deficient number, since it is larger than the sum of its proper divisors (13554095).

66831385 is a wasteful number, since it uses less digits than its factorization.

66831385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31307.

The product of its digits is 103680, while the sum is 40.

The square root of 66831385 is about 8175.0464830483. The cubic root of 66831385 is about 405.8138084352.

The spelling of 66831385 in words is "sixty-six million, eight hundred thirty-one thousand, three hundred eighty-five".