66531911 has 2 divisors, whose sum is σ = 66531912. Its totient is φ = 66531910.

The previous prime is 66531833. The next prime is 66531917. The reversal of 66531911 is 11913566.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66531911 - 2¹⁰ = 66530887 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66531917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33265955 + 33265956.

It is an arithmetic number, because the mean of its divisors is an integer number (33265956).

Almost surely, 2^66531911 is an apocalyptic number.

66531911 is a deficient number, since it is larger than the sum of its proper divisors (1).

66531911 is an equidigital number, since it uses as much as digits as its factorization.

66531911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4860, while the sum is 32.

The square root of 66531911 is about 8156.7095694281. The cubic root of 66531911 is about 405.2067450242.

The spelling of 66531911 in words is "sixty-six million, five hundred thirty-one thousand, nine hundred eleven".