66061409 has 2 divisors, whose sum is σ = 66061410. Its totient is φ = 66061408.

The previous prime is 66061393. The next prime is 66061417. The reversal of 66061409 is 90416066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52519009 + 13542400 = 7247^2 + 3680^2 .

It is a cyclic number.

It is not a de Polignac number, because 66061409 - 2⁴ = 66061393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (66001409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33030704 + 33030705.

It is an arithmetic number, because the mean of its divisors is an integer number (33030705).

Almost surely, 2^66061409 is an apocalyptic number.

It is an amenable number.

66061409 is a deficient number, since it is larger than the sum of its proper divisors (1).

66061409 is an equidigital number, since it uses as much as digits as its factorization.

66061409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 66061409 is about 8127.8169885892. The cubic root of 66061409 is about 404.2493008398.

The spelling of 66061409 in words is "sixty-six million, sixty-one thousand, four hundred nine".