6661213 has 8 divisors (see below), whose sum is σ = 7421400. Its totient is φ = 5936448.

The previous prime is 6661211. The next prime is 6661217. The reversal of 6661213 is 3121666.

It can be written as a sum of positive squares in 4 ways, for example, as 15129 + 6646084 = 123^2 + 2578^2 .

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 6661213 - 2¹ = 6661211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6661211) 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, 8458 + ... + 9211.

It is an arithmetic number, because the mean of its divisors is an integer number (927675).

Almost surely, 2^6661213 is an apocalyptic number.

It is an amenable number.

6661213 is a deficient number, since it is larger than the sum of its proper divisors (760187).

6661213 is a wasteful number, since it uses less digits than its factorization.

6661213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17711.

The product of its digits is 1296, while the sum is 25.

The square root of 6661213 is about 2580.9325833892. The cubic root of 6661213 is about 188.1558708072.

Adding to 6661213 its reverse (3121666), we get a palindrome (9782879).

The spelling of 6661213 in words is "six million, six hundred sixty-one thousand, two hundred thirteen".