66231811 has 2 divisors, whose sum is σ = 66231812. Its totient is φ = 66231810.

The previous prime is 66231799. The next prime is 66231817. The reversal of 66231811 is 11813266.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66231811 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66231811.

It is not a weakly prime, because it can be changed into another prime (66231817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33115905 + 33115906.

It is an arithmetic number, because the mean of its divisors is an integer number (33115906).

Almost surely, 2^66231811 is an apocalyptic number.

66231811 is a deficient number, since it is larger than the sum of its proper divisors (1).

66231811 is an equidigital number, since it uses as much as digits as its factorization.

66231811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 66231811 is about 8138.2928799595. The cubic root of 66231811 is about 404.5965824918.

The spelling of 66231811 in words is "sixty-six million, two hundred thirty-one thousand, eight hundred eleven".