66561359 has 2 divisors, whose sum is σ = 66561360. Its totient is φ = 66561358.

The previous prime is 66561349. The next prime is 66561373. The reversal of 66561359 is 95316566.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66561359 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66561349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33280679 + 33280680.

It is an arithmetic number, because the mean of its divisors is an integer number (33280680).

Almost surely, 2^66561359 is an apocalyptic number.

66561359 is a deficient number, since it is larger than the sum of its proper divisors (1).

66561359 is an equidigital number, since it uses as much as digits as its factorization.

66561359 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145800, while the sum is 41.

The square root of 66561359 is about 8158.5145093945. The cubic root of 66561359 is about 405.2665196896.

The spelling of 66561359 in words is "sixty-six million, five hundred sixty-one thousand, three hundred fifty-nine".