66081541 has 4 divisors (see below), whose sum is σ = 66762892. Its totient is φ = 65400192.

The previous prime is 66081511. The next prime is 66081557. The reversal of 66081541 is 14518066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 29430625 + 36650916 = 5425^2 + 6054^2 .

It is a cyclic number.

It is not a de Polignac number, because 66081541 - 2²³ = 57692933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66081511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 340530 + ... + 340723.

It is an arithmetic number, because the mean of its divisors is an integer number (16690723).

Almost surely, 2^66081541 is an apocalyptic number.

It is an amenable number.

66081541 is a deficient number, since it is larger than the sum of its proper divisors (681351).

66081541 is an equidigital number, since it uses as much as digits as its factorization.

66081541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 681350.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 66081541 is about 8129.0553571740. The cubic root of 66081541 is about 404.2903612232.

The spelling of 66081541 in words is "sixty-six million, eighty-one thousand, five hundred forty-one".