66374521 has 2 divisors, whose sum is σ = 66374522. Its totient is φ = 66374520.

The previous prime is 66374513. The next prime is 66374557. The reversal of 66374521 is 12547366.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 66259600 + 114921 = 8140^2 + 339^2 .

It is a cyclic number.

It is not a de Polignac number, because 66374521 - 2³ = 66374513 is a prime.

It is not a weakly prime, because it can be changed into another prime (66374821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33187260 + 33187261.

It is an arithmetic number, because the mean of its divisors is an integer number (33187261).

Almost surely, 2^66374521 is an apocalyptic number.

It is an amenable number.

66374521 is a deficient number, since it is larger than the sum of its proper divisors (1).

66374521 is an equidigital number, since it uses as much as digits as its factorization.

66374521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 34.

The square root of 66374521 is about 8147.0559713310. The cubic root of 66374521 is about 404.8869694228.

The spelling of 66374521 in words is "sixty-six million, three hundred seventy-four thousand, five hundred twenty-one".