665515481 has 2 divisors, whose sum is σ = 665515482. Its totient is φ = 665515480.

The previous prime is 665515469. The next prime is 665515553. The reversal of 665515481 is 184515566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 387459856 + 278055625 = 19684^2 + 16675^2 .

It is a cyclic number.

It is not a de Polignac number, because 665515481 - 2¹⁴ = 665499097 is a prime.

It is a super-2 number, since 2×665515481² = 885821710901322722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (665515681) 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, 332757740 + 332757741.

It is an arithmetic number, because the mean of its divisors is an integer number (332757741).

Almost surely, 2^665515481 is an apocalyptic number.

It is an amenable number.

665515481 is a deficient number, since it is larger than the sum of its proper divisors (1).

665515481 is an equidigital number, since it uses as much as digits as its factorization.

665515481 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144000, while the sum is 41.

The square root of 665515481 is about 25797.5867282194. The cubic root of 665515481 is about 873.0773483801.

The spelling of 665515481 in words is "six hundred sixty-five million, five hundred fifteen thousand, four hundred eighty-one".