66042541 has 4 divisors (see below), whose sum is σ = 68319900. Its totient is φ = 63765184.

The previous prime is 66042533. The next prime is 66042551. The reversal of 66042541 is 14524066.

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 40832100 + 25210441 = 6390^2 + 5021^2 .

It is a cyclic number.

It is not a de Polignac number, because 66042541 - 2³ = 66042533 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 (66042551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1138636 + ... + 1138693.

It is an arithmetic number, because the mean of its divisors is an integer number (17079975).

Almost surely, 2^66042541 is an apocalyptic number.

It is an amenable number.

66042541 is a deficient number, since it is larger than the sum of its proper divisors (2277359).

66042541 is a wasteful number, since it uses less digits than its factorization.

66042541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2277358.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 66042541 is about 8126.6562004308. The cubic root of 66042541 is about 404.2108108843.

The spelling of 66042541 in words is "sixty-six million, forty-two thousand, five hundred forty-one".