66411409 has 2 divisors, whose sum is σ = 66411410. Its totient is φ = 66411408.

The previous prime is 66411383. The next prime is 66411427. The reversal of 66411409 is 90411466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57047809 + 9363600 = 7553^2 + 3060^2 .

It is a cyclic number.

It is not a de Polignac number, because 66411409 - 2⁵ = 66411377 is a prime.

It is not a weakly prime, because it can be changed into another prime (66411109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33205704 + 33205705.

It is an arithmetic number, because the mean of its divisors is an integer number (33205705).

Almost surely, 2^66411409 is an apocalyptic number.

It is an amenable number.

66411409 is a deficient number, since it is larger than the sum of its proper divisors (1).

66411409 is an equidigital number, since it uses as much as digits as its factorization.

66411409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 66411409 is about 8149.3195421458. The cubic root of 66411409 is about 404.9619615751.

The spelling of 66411409 in words is "sixty-six million, four hundred eleven thousand, four hundred nine".