66111213 has 16 divisors (see below), whose sum is σ = 104215680. Its totient is φ = 36474816.

The previous prime is 66111197. The next prime is 66111233. The reversal of 66111213 is 31211166.

It is not a de Polignac number, because 66111213 - 2⁴ = 66111197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66111213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66111233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53670 + ... + 54887.

It is an arithmetic number, because the mean of its divisors is an integer number (6513480).

Almost surely, 2^66111213 is an apocalyptic number.

It is an amenable number.

66111213 is a deficient number, since it is larger than the sum of its proper divisors (38104467).

66111213 is a wasteful number, since it uses less digits than its factorization.

66111213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108596.

The product of its digits is 216, while the sum is 21.

The square root of 66111213 is about 8130.8802106537. The cubic root of 66111213 is about 404.3508637900.

Adding to 66111213 its reverse (31211166), we get a palindrome (97322379).

The spelling of 66111213 in words is "sixty-six million, one hundred eleven thousand, two hundred thirteen".