66071811 has 16 divisors (see below), whose sum is σ = 95225760. Its totient is φ = 40508160.

The previous prime is 66071791. The next prime is 66071821. The reversal of 66071811 is 11817066.

It is a happy number.

It is not a de Polignac number, because 66071811 - 2¹⁴ = 66055427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66071821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7945 + ... + 13973.

It is an arithmetic number, because the mean of its divisors is an integer number (5951610).

Almost surely, 2^66071811 is an apocalyptic number.

66071811 is a deficient number, since it is larger than the sum of its proper divisors (29153949).

66071811 is a wasteful number, since it uses less digits than its factorization.

66071811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6326.

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 66071811 is about 8128.4568646207. The cubic root of 66071811 is about 404.2705173645.

Adding to 66071811 its reverse (11817066), we get a palindrome (77888877).

The spelling of 66071811 in words is "sixty-six million, seventy-one thousand, eight hundred eleven".