665500000091 has 2 divisors, whose sum is σ = 665500000092. Its totient is φ = 665500000090.

The previous prime is 665500000057. The next prime is 665500000117. The reversal of 665500000091 is 190000005566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 665500000091 - 2²² = 665495805787 is a prime.

It is a super-2 number, since 2×665500000091² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (665500000391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332750000045 + 332750000046.

It is an arithmetic number, because the mean of its divisors is an integer number (332750000046).

Almost surely, 2^665500000091 is an apocalyptic number.

665500000091 is a deficient number, since it is larger than the sum of its proper divisors (1).

665500000091 is an equidigital number, since it uses as much as digits as its factorization.

665500000091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8100, while the sum is 32.

The spelling of 665500000091 in words is "six hundred sixty-five billion, five hundred million, ninety-one", and thus it is an aban number.