165276397681 has 2 divisors, whose sum is σ = 165276397682. Its totient is φ = 165276397680.

The previous prime is 165276397667. The next prime is 165276397711. The reversal of 165276397681 is 186793672561.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141589648656 + 23686749025 = 376284^2 + 153905^2 .

It is an emirp because it is prime and its reverse (186793672561) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 165276397681 - 2¹³ = 165276389489 is a prime.

It is a super-2 number, since 2×165276397681² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (165276397651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82638198840 + 82638198841.

It is an arithmetic number, because the mean of its divisors is an integer number (82638198841).

Almost surely, 2^165276397681 is an apocalyptic number.

It is an amenable number.

165276397681 is a deficient number, since it is larger than the sum of its proper divisors (1).

165276397681 is an equidigital number, since it uses as much as digits as its factorization.

165276397681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22861440, while the sum is 61.

The spelling of 165276397681 in words is "one hundred sixty-five billion, two hundred seventy-six million, three hundred ninety-seven thousand, six hundred eighty-one".