666013321 has 8 divisors (see below), whose sum is σ = 668646440. Its totient is φ = 663386112.

The previous prime is 666013303. The next prime is 666013343. The reversal of 666013321 is 123310666.

666013321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 65028096 + 600985225 = 8064^2 + 24515^2 .

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 666013321 - 2¹¹ = 666011273 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 666013321.

It is not an unprimeable number, because it can be changed into a prime (666013351) 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, 446545 + ... + 448033.

It is an arithmetic number, because the mean of its divisors is an integer number (83580805).

Almost surely, 2^666013321 is an apocalyptic number.

It is an amenable number.

666013321 is a deficient number, since it is larger than the sum of its proper divisors (2633119).

666013321 is a wasteful number, since it uses less digits than its factorization.

666013321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2955.

The product of its (nonzero) digits is 3888, while the sum is 28.

The square root of 666013321 is about 25807.2338889700. The cubic root of 666013321 is about 873.2949964557.

Adding to 666013321 its reverse (123310666), we get a palindrome (789323987).

It can be divided in two parts, 6660 and 13321, that multiplied together give a triangular number (88717860 = T₁₃₃₂₀).

The spelling of 666013321 in words is "six hundred sixty-six million, thirteen thousand, three hundred twenty-one".