66542111 has 2 divisors, whose sum is σ = 66542112. Its totient is φ = 66542110.

The previous prime is 66542107. The next prime is 66542129. The reversal of 66542111 is 11124566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66542111 - 2² = 66542107 is a prime.

It is a Sophie Germain prime.

It is a nialpdrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66542101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33271055 + 33271056.

It is an arithmetic number, because the mean of its divisors is an integer number (33271056).

Almost surely, 2^66542111 is an apocalyptic number.

66542111 is a deficient number, since it is larger than the sum of its proper divisors (1).

66542111 is an equidigital number, since it uses as much as digits as its factorization.

66542111 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 26.

The square root of 66542111 is about 8157.3347975917. The cubic root of 66542111 is about 405.2274513667.

Adding to 66542111 its reverse (11124566), we get a palindrome (77666677).

The spelling of 66542111 in words is "sixty-six million, five hundred forty-two thousand, one hundred eleven".