66091799 has 2 divisors, whose sum is σ = 66091800. Its totient is φ = 66091798.

The previous prime is 66091793. The next prime is 66091807. The reversal of 66091799 is 99719066.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66091799 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 (66091793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33045899 + 33045900.

It is an arithmetic number, because the mean of its divisors is an integer number (33045900).

Almost surely, 2^66091799 is an apocalyptic number.

66091799 is a deficient number, since it is larger than the sum of its proper divisors (1).

66091799 is an equidigital number, since it uses as much as digits as its factorization.

66091799 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 183708, while the sum is 47.

The square root of 66091799 is about 8129.6862793099. The cubic root of 66091799 is about 404.3112798030.

The spelling of 66091799 in words is "sixty-six million, ninety-one thousand, seven hundred ninety-nine".