165515810491 has 2 divisors, whose sum is σ = 165515810492. Its totient is φ = 165515810490.

The previous prime is 165515810479. The next prime is 165515810503. The reversal of 165515810491 is 194018515561.

165515810491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (165515810479) and next prime (165515810503).

It is a cyclic number.

It is not a de Polignac number, because 165515810491 - 2¹¹ = 165515808443 is a prime.

It is a super-2 number, since 2×165515810491² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165515810891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82757905245 + 82757905246.

It is an arithmetic number, because the mean of its divisors is an integer number (82757905246).

Almost surely, 2^165515810491 is an apocalyptic number.

165515810491 is a deficient number, since it is larger than the sum of its proper divisors (1).

165515810491 is an equidigital number, since it uses as much as digits as its factorization.

165515810491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216000, while the sum is 46.

The spelling of 165515810491 in words is "one hundred sixty-five billion, five hundred fifteen million, eight hundred ten thousand, four hundred ninety-one".