66826789 has 2 divisors, whose sum is σ = 66826790. Its totient is φ = 66826788.

The previous prime is 66826733. The next prime is 66826841. The reversal of 66826789 is 98762866.

It is an a-pointer prime, because the next prime (66826841) can be obtained adding 66826789 to its sum of digits (52).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64160100 + 2666689 = 8010^2 + 1633^2 .

It is a cyclic number.

It is not a de Polignac number, because 66826789 - 2¹⁹ = 66302501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66826489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33413394 + 33413395.

It is an arithmetic number, because the mean of its divisors is an integer number (33413395).

Almost surely, 2^66826789 is an apocalyptic number.

It is an amenable number.

66826789 is a deficient number, since it is larger than the sum of its proper divisors (1).

66826789 is an equidigital number, since it uses as much as digits as its factorization.

66826789 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1741824, while the sum is 52.

The square root of 66826789 is about 8174.7653788962. The cubic root of 66826789 is about 405.8045056053.

The spelling of 66826789 in words is "sixty-six million, eight hundred twenty-six thousand, seven hundred eighty-nine".