66457789 has 2 divisors, whose sum is σ = 66457790. Its totient is φ = 66457788.

The previous prime is 66457771. The next prime is 66457799. The reversal of 66457789 is 98775466.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64080025 + 2377764 = 8005^2 + 1542^2 .

It is a cyclic number.

It is not a de Polignac number, because 66457789 - 2⁵ = 66457757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66457799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33228894 + 33228895.

It is an arithmetic number, because the mean of its divisors is an integer number (33228895).

Almost surely, 2^66457789 is an apocalyptic number.

It is an amenable number.

66457789 is a deficient number, since it is larger than the sum of its proper divisors (1).

66457789 is an equidigital number, since it uses as much as digits as its factorization.

66457789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2540160, while the sum is 52.

The square root of 66457789 is about 8152.1646818498. The cubic root of 66457789 is about 405.0562112702.

The spelling of 66457789 in words is "sixty-six million, four hundred fifty-seven thousand, seven hundred eighty-nine".