66826213 has 4 divisors (see below), whose sum is σ = 66866508. Its totient is φ = 66785920.

The previous prime is 66826183. The next prime is 66826229. The reversal of 66826213 is 31262866.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22297284 + 44528929 = 4722^2 + 6673^2 .

It is a cyclic number.

It is not a de Polignac number, because 66826213 - 2¹³ = 66818021 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 (66826313) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17548 + ... + 21013.

It is an arithmetic number, because the mean of its divisors is an integer number (16716627).

Almost surely, 2^66826213 is an apocalyptic number.

It is an amenable number.

66826213 is a deficient number, since it is larger than the sum of its proper divisors (40295).

66826213 is a wasteful number, since it uses less digits than its factorization.

66826213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40294.

The product of its digits is 20736, while the sum is 34.

The square root of 66826213 is about 8174.7301484514. The cubic root of 66826213 is about 405.8033396853.

The spelling of 66826213 in words is "sixty-six million, eight hundred twenty-six thousand, two hundred thirteen".