66581461 has 2 divisors, whose sum is σ = 66581462. Its totient is φ = 66581460.

The previous prime is 66581443. The next prime is 66581483. The reversal of 66581461 is 16418566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65707236 + 874225 = 8106^2 + 935^2 .

It is a cyclic number.

It is not a de Polignac number, because 66581461 - 2¹⁷ = 66450389 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66581461.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66581161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33290730 + 33290731.

It is an arithmetic number, because the mean of its divisors is an integer number (33290731).

Almost surely, 2^66581461 is an apocalyptic number.

It is an amenable number.

66581461 is a deficient number, since it is larger than the sum of its proper divisors (1).

66581461 is an equidigital number, since it uses as much as digits as its factorization.

66581461 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 37.

The square root of 66581461 is about 8159.7463808626. The cubic root of 66581461 is about 405.3073133659.

The spelling of 66581461 in words is "sixty-six million, five hundred eighty-one thousand, four hundred sixty-one".