66540553 has 2 divisors, whose sum is σ = 66540554. Its totient is φ = 66540552.

The previous prime is 66540521. The next prime is 66540563. The reversal of 66540553 is 35504566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 63808144 + 2732409 = 7988^2 + 1653^2 .

It is a cyclic number.

It is not a de Polignac number, because 66540553 - 2⁵ = 66540521 is a prime.

It is not a weakly prime, because it can be changed into another prime (66540563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33270276 + 33270277.

It is an arithmetic number, because the mean of its divisors is an integer number (33270277).

Almost surely, 2^66540553 is an apocalyptic number.

It is an amenable number.

66540553 is a deficient number, since it is larger than the sum of its proper divisors (1).

66540553 is an equidigital number, since it uses as much as digits as its factorization.

66540553 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54000, while the sum is 34.

The square root of 66540553 is about 8157.2393001554. The cubic root of 66540553 is about 405.2242887113.

The spelling of 66540553 in words is "sixty-six million, five hundred forty thousand, five hundred fifty-three".